Is there a good reason for Synology to change the support of “Unverified Drives” in DSM?

Synology has long been regarded as one of the most user-friendly and reliable NAS brands in the market, balancing intuitive software with a wide hardware range that appeals to both home and business users. However, in recent years the company has taken an increasingly controversial path by enforcing strict compatibility requirements for hard drives and SSDs. Beginning with DSM 7 and escalating into the 2025 generation of devices, Synology now only certifies and supports its own branded storage media, effectively locking out many widely used alternatives from Seagate, Western Digital, and Toshiba. While Synology positions this move as a way to ensure system stability and consistency, the decision has sparked significant backlash among users who feel restricted in their options and burdened by higher costs. As competitors expand their ecosystems with more openness and flexibility, this proprietary approach risks damaging Synology’s reputation, raising questions about whether the company has prioritized profit margins over user choice.

What is the MAIN PROBLEM(s) with this decision by Synology?

The most immediate problem with Synology’s hard drive policy is the loss of flexibility that once made their systems so appealing. For years, customers could select from a wide range of industry-standard drives from Seagate, Western Digital, or Toshiba, tailoring storage to their budget, performance requirements, or regional availability. This freedom not only allowed users to balance cost and capacity, but also gave small businesses and home enthusiasts the ability to reuse existing drives, upgrade incrementally, or take advantage of promotions from different vendors. By restricting DSM compatibility to Synology-labelled drives, that flexibility is gone. For many users outside major markets, Synology’s drives are harder to source, priced higher than the competition, or limited in available capacities. What once felt like an open platform now increasingly resembles a closed ecosystem, where users must accept the vendor’s terms even if it means compromising on affordability or performance.

Another dimension of the problem lies in how Synology has communicated these changes, which many see as evasive or disingenuous. Officially, the company justifies the restriction as a move toward greater reliability and predictable system performance. The argument is that by narrowing the range of drives tested and supported, Synology can optimize DSM to work seamlessly with drives that have firmware tailored for its environment. In practice, though, the same underlying hardware often originates from Seagate or Toshiba, with only minor firmware adjustments and new branding. This creates a perception that Synology is overstating the technical benefits while quietly using the policy to secure higher margins. For long-time users, the contrast is stark: older models happily ran third-party drives with few issues, which makes the sudden insistence on “certification” seem less like an engineering requirement and more like a business maneuver. The result has been a significant erosion of trust between the company and its community.

The wider impact of this strategy has also been felt across the storage industry. Resellers have reported declining sales of Synology’s Plus series devices as customers explore alternatives such as QNAP, TrueNAS, or newer entrants like UGREEN and UniFi. For Synology, this shift is particularly damaging because its reputation has historically rested on attracting less technical buyers who value simplicity and reliability over DIY solutions. Now, even these entry-level and mid-range users are questioning whether they should commit to an ecosystem that limits their choice of drives and increases their costs. At the same time, hard drive manufacturers like Seagate and Western Digital are also affected, as Synology’s decision reduces the number of channels through which their products reach end customers. The ripple effect is therefore twofold: Synology risks alienating its base of loyal customers, while storage vendors lose a once-reliable partner, creating tension that could ultimately push more buyers toward competing NAS brands.

How Can Synology Solve This (if they want to)?

One path forward for Synology would be to adopt a hybrid compatibility model, where its own branded drives remain the recommended or default choice but third-party alternatives are still officially supported. This compromise has been proven by other vendors such as UniFi and QNAP, who sell their own labelled drives while maintaining compatibility lists for major manufacturers like Seagate, Western Digital, and Toshiba. By following this model, Synology could continue promoting the reliability benefits of its branded hardware without alienating customers who prefer flexibility. In practice, this would preserve a sense of choice for users while ensuring Synology can still highlight its “optimized” solutions as the safer, supported route.

Finally, Synology could address the availability and pricing concerns around its own branded drives. In many regions, these drives are either difficult to source or significantly more expensive than equivalent Seagate or Western Digital models. Improving distribution channels, ensuring consistent stock, and narrowing the price gap would make the transition more palatable to users who are willing to adopt Synology’s ecosystem but feel penalized by limited access. By focusing on accessibility and fairness rather than exclusivity, Synology could rebuild goodwill while still driving revenue from its hardware strategy. Taken together, these steps would not fully reverse the controversy but would demonstrate responsiveness and provide a clearer path to balancing stability, customer choice, and profitability.

Is there a way to FORCE a Synology NAS to accept unverified Hard Drives and SSDs in DSM?

For users unwilling to accept Synology’s restrictive stance on storage media, the community has developed reliable workarounds that re-enable full functionality for third-party hard drives and SSDs. The most widely adopted method involves injecting a script into the NAS system that bypasses DSM’s compatibility database, allowing otherwise unsupported drives to be used for installation, storage pools, caching, and expansion. Synology’s 2025 Plus-series models, such as the DS925+, block DSM installation if only unverified drives are present and issue constant warnings in Storage Manager. To overcome this, users first employ a Telnet-based flag during initial setup that tricks DSM into accepting the installation, followed by a more permanent fix applied through SSH. At the heart of this solution is Dave Russell’s (007revad) GitHub project Synology_HDD_db, which modifies DSM’s internal drive compatibility files. Once downloaded and executed via SSH, the script detects the NAS model, DSM version, and connected drives, then patches the system to treat them as officially supported.

The process is reversible, non-destructive, and works across multiple DSM versions, including DSM 7.2 and later. Additional features allow removal of persistent warning banners, full use of NVMe drives as storage volumes, and optional disabling of intrusive monitoring services like WDDA. To ensure ongoing stability, users can also configure a scheduled task in DSM’s Task Scheduler that re-applies the script at every boot, guaranteeing compatibility survives updates, reboots, or new drive insertions. While the script is robust and actively maintained, there are clear disclaimers: using it involves modifying system files, may void official Synology support, and should only be attempted by users confident with SSH and terminal commands who have reliable data backups. Nonetheless, for advanced users, system integrators, and enthusiasts, this community-driven solution has become the de facto method of restoring the freedom to use affordable and widely available third-party drives in modern Synology NAS systems.

Example of a 30TB Seagate HDD visible and functioning inside a Synology DS925+

Note – You can follow my guide on how to use this script modification (as well as outlining the pros and cons) HERE on the blog, or watch the video below:

The Future of Synology in the eyes of new and old buyers?

Synology’s decision to enforce exclusive support for its own branded hard drives and SSDs marks one of the most controversial shifts in the company’s history, transforming how both long-time customers and potential buyers view the brand. For over a decade, Synology’s appeal rested on a combination of intuitive software, solid hardware, and flexibility in allowing users to choose their own storage media from trusted vendors like Seagate, Toshiba, and Western Digital. By removing that choice in the 2025 generation, Synology has fundamentally altered the value proposition of its systems, making them appear less like open storage platforms and more like tightly controlled appliances. While the company justifies the policy by citing stability, predictability, and reduced support overhead, many users interpret it as a profit-driven attempt to push proprietary drives into the market, especially since these are often rebranded versions of third-party disks with modified firmware and higher price tags.

The backlash has been considerable, with resellers and community forums reporting falling interest in Synology’s Plus-series devices, particularly among home and small business users who previously embraced them for affordability and ease of expansion. Competing NAS providers such as QNAP, TrueNAS, UGREEN, and UniFi have been quick to capitalize on the discontent, positioning themselves as more open alternatives that maintain compatibility with industry-standard drives. At the same time, the growth of unofficial solutions like Dave Russell’s compatibility script demonstrates how determined users are to regain control over their hardware, even at the risk of voiding warranty or stepping outside official support. This dynamic reflects a widening gap between Synology’s official direction and the needs of its customer base, many of whom would prefer to accept a disclaimer about using unverified drives rather than being forced into a closed ecosystem.

Ultimately, Synology now stands at a crossroads that will define its reputation in the storage industry for years to come. If it continues to double down on a closed, proprietary model, the company may secure short-term revenue through drive sales but risks long-term damage to its image and market share. On the other hand, reintroducing a more flexible, transparent approach—such as allowing user consent for unsupported drives or improving global pricing and availability of its own disks—could restore trust and preserve its standing as the NAS brand of choice for both novices and professionals. The availability of community workarounds ensures that frustrated users are not entirely locked out of their systems, but the very existence of these tools highlights how far Synology has drifted from its once customer-first ethos. The next few years will be crucial, as the company either adjusts course and strikes a balance between profitability and user freedom, or risks ceding ground to rivals who are eager to embrace the openness Synology has chosen to leave behind.

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Use Whatever Hard Drives or SSDs on Your Synology NAS (2025 Guide)

Note – there is a YouTube tutorial version of this guide HERE on the NASCompares YouTube Channel

Synology’s 2025 generation of NAS systems, such as the DS925+ and other Plus series models, introduced a more restrictive approach to drive compatibility. Unlike previous generations, these devices enforce a compatibility check that blocks or limits functionality when non-Synology hard drives or SSDs are used. As a result, users are unable to install DSM, create storage pools, or configure caching volumes using unverified drives. Even drives that work in earlier Synology models are now flagged as unsupported, resulting in persistent alerts or outright refusal to function. This guide provides a complete walkthrough for users who want to bypass those restrictions and enable full usage of third-party SATA and NVMe drives, including for pools, volumes, hot spares, and cache. It includes step-by-step instructions on how to install DSM with only unverified drives, how to remove system warnings, and how to automate the process for future updates or drive additions. The solutions here rely on trusted scripts developed by the Synology community and require minimal system modification, allowing users to regain control over their own hardware.

Special Thanks to Dave Russell

The ability to bypass Synology’s restrictive drive compatibility checks would not be possible without the extensive work of Dave Russell, widely known in the Synology community as 007revad. His GitHub project, Synology_HDD_db, is the basis for all the procedures outlined in this guide. The script he developed modifies DSM’s internal compatibility database, enabling full functionality for otherwise unsupported HDDs, SSDs, and NVMe drives. Dave has not only written and maintained this complex script, but also ensured that it works across different NAS models and DSM versions, including DSM 7.2 and newer. He continues to improve the tool in response to Synology firmware changes, regularly providing updates and extended options such as M.2 volume support and WDDA disablement. Users are strongly encouraged to consult the official GitHub repository, follow the provided documentation, and, where possible, support his ongoing work HERE, which remains freely available to the broader NAS community.

MASSIVE Disclaimer

Modifying your Synology NAS to allow the use of unverified drives is not officially supported by Synology. By applying the changes described in this guide, you will be altering system files and bypassing built-in compatibility checks within DSM. While these changes are reversible and have been widely tested, doing so may void your Synology warranty or affect your ability to receive technical support from the manufacturer, even in cases unrelated to storage. Additionally, although the script-based method described here is non-destructive and has proven safe for many users, there is always a minimal risk of issues following DSM updates or hardware changes. You should not proceed unless you have full backups of your data and are comfortable with SSH and terminal operations. This guide is intended for advanced users, system integrators, or home NAS enthusiasts who understand the risks and accept responsibility for operating outside of official Synology support channels.

How to Set Up a Synology NAS with No Drives Installed to Allow DSM Installation

Synology’s 2025 and later Plus-series NAS systems will not allow DSM installation if only unverified drives are present. However, it is possible to bypass this limitation and install DSM without using any Synology-branded or officially supported drives. The method involves enabling Telnet access and overriding the drive compatibility check during the DSM installation process.

Step-by-Step Instructions:

• Physically set up your NAS

  • Connect the NAS to your local network using Ethernet.

  • Ensure the device is powered on, even if no drives are installed or only unverified drives are present.

• Attempt initial DSM setup

  • Use Synology Assistant or go to http://find.synology.com to locate your NAS.

  • Proceed through the DSM installation wizard. You will likely encounter an error indicating that the inserted drive(s) are unsupported.

• Enable Telnet access

  • In a browser, navigate to:
    http://<NAS-IP>:5000/webman/start_telnet.cgi
    Replace <NAS-IP> with the actual IP address of your NAS.

• Connect via Telnet

  • Open a Telnet client like PuTTY.

  • Enter your NAS IP address and connect via Telnet.

  • When prompted, use:

    • Username: root

    • Password: 101-0101 (default for this Telnet interface)

• Bypass installation check

  • Enter the following command into the Telnet window:

    while true; do touch /tmp/installable_check_pass; sleep 1; done


  • This creates a temporary flag that bypasses the system’s compatibility verification loop.

• Return to the DSM install page

  • Refresh the browser window where you began the DSM setup.

  • DSM will now allow installation to proceed, even on unverified drives.

• Finish DSM setup

  • Complete the DSM installation.

  • Create your admin user account when prompted.

  • You can now access the full DSM interface.

Once DSM is installed, you can proceed to apply the permanent drive compatibility fixes, create storage pools, and remove warning banners—all covered in the next section.

How to Allow Unverified HDDs or SSDs to Be Used for Storage Pools, Volumes, and Caching (and Remove Warnings)

Once DSM is installed, unverified drives will still be blocked from creating storage pools, volumes, or caches. Even if the system boots, Storage Manager will display warnings or greyed-out options. To unlock full functionality, you must apply a community-developed script that updates DSM’s internal drive compatibility database. This section outlines how to download, apply, and validate that change.

Step-by-Step Instructions:

• Enable SSH on your NAS
  • In DSM, go to Control Panel > Terminal & SNMP > Terminal.
  • Enable SSH service and click Apply.

• Prepare SSH access
  • Use PuTTY (or your preferred SSH client) to connect to your NAS.
  • Log in using your DSM administrator username and password (not root at this stage).
• Create working directory
  • Once connected, elevate to root:

    sudo -i
    

  • Create the required folder:

    mkdir -m775 /opt
    cd /opt
    

• Download the required scripts
  • Run the following commands to download the latest versions directly from Dave Russell’s GitHub:

    curl -O "https://raw.githubusercontent.com/007revad/Synology_HDD_db/refs/heads/main/syno_hdd_db.sh"
    curl -O "https://raw.githubusercontent.com/007revad/Synology_HDD_db/refs/heads/main/syno_hdd_vendor_ids.txt"
    chmod 750 /opt/syno_hdd_db.sh
    

• Run the script
  • Execute the script to patch the drive database:

    /opt/syno_hdd_db.sh
    

  • The script will detect your NAS model, DSM version, and connected drives. It will then add those drives to the compatibility database and back up the original files.

• Check Storage Manager
  • Return to DSM’s Storage Manager.
  • If changes are not immediately visible, reboot your NAS.
  • You should now be able to create storage pools, volumes, and SSD caches with unverified drives, without warning messages.
• Optional: Disable compatibility warnings completely
  • To stop future drive alerts from DSM, you may also want to run:

    /usr/syno/bin/synosetkeyvalue /etc.defaults/synoinfo.conf support_disk_compatibility no
    

At this point, all third-party drives currently installed in the system will be fully usable and recognized as supported. The next section explains how to add additional unverified drives later and have them automatically accepted.

What to Do When Adding New HDDs or SSDs Later for Expansion, Replacement, or Hot Spares

After your initial setup and database modification, any newly added unverified drives will still appear as unsupported in DSM until they are explicitly added to the modified compatibility database. This section outlines how to safely introduce new drives for RAID expansion, hot spare assignment, or disk replacement without encountering blockages or warning messages.

Step-by-Step Instructions:

• Physically install the new drive(s)
  • Power down your NAS if required (for systems that don’t support hot-swapping).
  • Insert the new unverified HDDs or SSDs into available bays.
  • Power the NAS back on and log in to DSM.
• Check Storage Manager
  • Go to Storage Manager > HDD/SSD.
  • Newly added drives will appear but will be marked as “Not supported” or “Unverified.”
  • They will not be usable for volume expansion or as hot spares until added to the compatibility list.
• Reconnect via SSH
  • Use PuTTY or your SSH client to log into DSM with your admin credentials.
  • Elevate to root access:

    sudo -i
    

• Navigate to the working directory
  • Assuming you previously created /opt and stored the script there:

    cd /opt
    

• Run the update script again
  • This re-applies the database patch and includes newly inserted drives:

    ./syno_hdd_db.sh

1. Verify drive status
   • Go back to Storage Manager.
   • Refresh the page or reboot the NAS if needed.
   • The newly added drives should now appear as compatible and can be used for expansion, drive replacement, or assigned as hot spares.

This process can be repeated anytime new unverified drives are introduced. However, to avoid having to manually re-run the script every time, the next section covers how to set up a scheduled task that automates this during every system boot.

How to Set Up a Scheduled Task to Re-Apply the Fix on Every Reboot

Synology DSM updates or certain system operations can overwrite or reset the internal compatibility database, especially after version upgrades or service restarts. To ensure that unverified drives remain recognized and fully functional even after a reboot, you can configure a scheduled task that automatically re-applies the compatibility script at every startup.

Step-by-Step Instructions:

• Log in to DSM and open Task Scheduler
  • Go to Control Panel > Task Scheduler.
  • Click Create > Triggered Task > User-defined script.
• Configure the general settings
  • Task Name: Name it something descriptive like Drive Compatibility Patch.
  • User: Select root from the dropdown (this is essential for full system access).
  • Event: Select Boot-up so the script runs every time the NAS starts.
  • Leave Enabled checked.

• Set the script action
  • Click on the Task Settings tab.
  • In the User-defined script box, enter the following command:

    mkdir -m775 /opt
    cd /opt || (echo "Failed to CD to /opt"; exit 1)
    curl -O "https://raw.githubusercontent.com/007revad/Synology_HDD_db/refs/heads/main/syno_hdd_db.sh"
    curl -O "https://raw.githubusercontent.com/007revad/Synology_HDD_db/refs/heads/main/syno_hdd_vendor_ids.txt"
    chmod 750 /opt/syno_hdd_db.sh
    /opt/syno_hdd_db.sh -e
    

  • This ensures the script is always downloaded fresh and applied with the -e flag for compatibility with scheduled tasks and email output (if enabled).
• Optional email notifications
  • Still under Task Settings, you can enable email alerts to be notified if the script fails or terminates abnormally.
• Save and test
  • Click OK to save the task.
  • You can manually run the task to confirm it executes correctly.
  • Reboot the NAS to ensure the script is applied at boot and unverified drives remain fully usable.

This scheduled task ensures long-term reliability and reduces the need for manual intervention whenever DSM is restarted, updated, or new drives are introduced.

Synology’s decision to restrict drive compatibility in its 2025 and later NAS models has complicated matters for users who prefer flexibility in their storage choices. However, through a combination of Telnet access, SSH scripting, and community-built tools like Dave Russell’s syno_hdd_db.sh, it is entirely possible to restore full drive functionality—even when using completely unverified SATA or NVMe devices. By following the steps outlined in this guide, users can install DSM on unverified drives, create storage pools, use SSDs for caching, and expand or modify their RAID configurations without limitations. Setting up an automated scheduled task further ensures these capabilities persist through reboots and DSM updates. While Synology may eventually broaden official support, this method provides a reliable and reversible way to maintain full control over your hardware today.

Should You Buy the Synology DS925+ NAS?

In practical terms, the DS925+ is the stronger out-of-the-box choice, especially for users who value simplicity, improved default performance, and do not anticipate needing higher-than-2.5GbE networking down the line. However, the long-term value proposition becomes murkier when you factor in the DS923+’s PCIe expansion, broader drive compatibility, and the potential price drops that will follow its ageing status in Synology’s lineup. In short, the DS925+ is the better NAS on day one—more powerful, faster, and quieter. But if you’re planning for day 1,000, it’s worth pausing to consider whether the expandability and media flexibility of the DS923+ may be a better fit for your storage and networking needs over the next five to seven years.

Synology DS925+ NAS		Synology DS923+ NAS
Check Amazon in Your Region for the Synology DS925+ NAS	Check B&H for the Synology DS925+ NAS	Check Amazon in Your Region for the Synology DS923+ NAS	Check B&H for the Synology DS923+ NAS

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This description contains links to Amazon. These links will take you to some of the products mentioned in today's content. As an Amazon Associate, I earn from qualifying purchases. Visit the NASCompares Deal Finder to find the best place to buy this device in your region, based on Service, Support and Reputation - Just Search for your NAS Drive in the Box Below

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If you like this service, please consider supporting us. We use affiliate links on the blog allowing NAScompares information and advice service to be free of charge to you.Anything you purchase on the day you click on our links will generate a small commission which isused to run the website. Here is a link for Amazon and B&H.You can also get me a Ko-fi or old school Paypal. Thanks!To find out more about how to support this advice service check HEREIf you need to fix or configure a NAS, check Fiver Have you thought about helping others with your knowledge? Find Instructions Here  

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Synology Hard Drives and SSD Comparison with Seagate/WD/Toshiba and More – Deal Breaker?

In recent years, Synology has steadily moved toward a more vertically integrated hardware ecosystem, and the arrival of the 2025 generation of NAS systems marks a significant escalation in that approach. With a much stricter verification process for compatible storage media—covering both hard drives and SSDs—Synology now appears to heavily prioritize its own branded storage. This shift has sparked widespread debate across the NAS community, particularly as many long-time users of Seagate IronWolf, WD Red, and Toshiba NAS drives find themselves increasingly locked out of certain key features like RAID expansion, hot spare assignment, and recovery operations unless using “verified” drives. What’s more, while some of Synology’s media are rebranded and firmware-modified versions of familiar drives from Seagate and Toshiba, the pricing and compatibility limitations often leave users puzzled—and frustrated.

In response to growing user concern, we conducted a comparison of Synology’s drive lineup against the current offerings from Seagate, WD, and Kingston—analyzing each in terms of price per terabyte, real-world performance, durability specifications, and availability. Drawing from direct benchmarking, manufacturer datasheets, and controlled NAS testing environments, this article aims to answer a key question: is Synology’s branded media actually worth the premium? While some users may welcome the simplicity of a one-brand ecosystem, others are understandably wary of higher costs, limited SKU availability, and the potential long-term implications of vendor lock-in. Let’s break down what Synology drives really offer—and where they fall short—compared to the tried and tested alternatives on the market.

Synology Hard Drives and SSDs – What Drives Are There to Buy?

Synology’s storage media catalog is divided across value, prosumer, enterprise SATA, and SAS hard drives, alongside both SATA and NVMe SSDs. While these drives carry the Synology name and firmware, they are not designed or manufactured in-house. Instead, Synology rebrands OEM hardware from established vendors: Toshiba for the enterprise SATA and SAS drives, Seagate for the value-tier NAS HDDs, and Phison-based platforms for SSDs. The internal firmware is customized by Synology to integrate tightly with DSM, and in some cases, to restrict compatibility to only their branded drives within the latest 2025 NAS systems.

The naming scheme makes it easier to distinguish between drive classes:

• HAT for SATA NAS hard drives

• HAS for SAS enterprise drives

• SAT for SATA SSDs

• SNV for NVMe SSDs

This segmentation aims to help users align their hardware with expected durability (e.g. workload in TB/year), power loss protection, and RAID integration. However, it’s worth noting that several of these drives are virtually identical to third-party counterparts—particularly in the HAT3300 and HAT3310 lines, which closely mirror Seagate IronWolf models down to mechanical structure and spec. Despite this, third-party versions of those drives remain incompatible with key RAID features on the latest Synology systems unless they are officially “verified.”

Synology NAS HDDs – HAT Series (SATA)

Model	Capacity	Price (USD)	$/TB
HAT3300	2TB	$84.99	$42.50
	4TB	$99.99	$25.00
	6TB	$149.99	$25.00
HAT3310	8TB	$199.99	$25.00
	12TB	$269.99	$22.50
	12TB (2-Pack)	$539.98	$22.50
	16TB	$299.99	$18.75
HAT5300 (Enterprise, Toshiba)	12TB	$449.99	$37.50
	16TB	$579.99	$36.25
HAT5310	8TB	$299.99	$37.50
	20TB	$719.99	$36.00

Synology SAS HDDs – HAS Series

Model	Capacity	Price (USD)	$/TB
HAS5300	8TB	$299.99	$37.50
	12TB	$459.99	$38.33
	16TB	$699.99	$43.75
HAS5310	20TB	$829.99	$41.50

Synology SATA SSDs – SAT Series

Model	Capacity	Price (USD)	$/TB
SAT5210	7TB	$1,859.99	$265.71
SAT5221	480GB	$169.99	$354.15
	960GB	$299.99	$312.49
	1.92TB	$529.99	$276.04
	3.84TB	$979.99	$255.20

Synology NVMe SSDs – SNV Series

Model	Capacity	Price (USD)	$/TB
SNV3410	400GB	$139.99	$349.98
	800GB	$269.99	$337.49
SNV3510	400GB	$174.99	$437.48
	800GB	$299.99	$374.99

While Synology’s branding suggests ecosystem cohesion, it’s essential to recognize that their drive firmware is not engineered for general-purpose systems. These drives are optimized—and in some cases restricted—for Synology NAS environments. However, performance benchmarks show that Synology drives often perform equivalently or slightly below their third-party counterparts in synthetic and real-world tests. Moreover, price comparisons reveal a 5–15% markup on average in the value tier, and significantly higher deltas—often exceeding 30–40%—in the enterprise-class and SSD segments. Combined with regional supply inconsistencies and limited SKU availability, the value proposition of Synology-branded drives remains hotly debated, especially when identical hardware from Seagate or Toshiba can be purchased for less—if only the 2025 NAS series would support them natively.

Synology Hard Drives and SSDs vs Seagate, WD, etc – Price per TB and Value

When it comes to entry-level NAS hard drives, the price differences between Synology’s HAT3300 and HAT3310 series and their third-party equivalents—such as Seagate IronWolf and WD Red Plus—are generally modest. In most cases, the cost per terabyte (TB) stays within a 0% to 15% margin, with Synology’s versions sitting slightly higher. For casual or home users who just want a drive that “just works” out of the box and benefits from firmware-level integration with DSM, that small premium might feel justifiable.

But the story changes dramatically as we move into prosumer and enterprise territory. Drives like the Synology HAT5300 and HAS5300 series can cost 40%–50% more than Seagate IronWolf Pro, WD Red Pro, or Seagate Exos alternatives—despite sharing the same mechanical internals in many cases. These aren’t just marginal differences; when you’re building a multi-drive RAID array with 12TB or 16TB drives, that pricing gap quickly snowballs into hundreds or even thousands of dollars extra. And this is particularly frustrating when, for example, Synology’s 12TB HAT5300 (built on Toshiba hardware) costs nearly double what a comparable IronWolf Pro sells for, despite similar endurance ratings and warranty terms.

Entry-Level NAS HDDs – Synology vs Seagate & WD

Synology Model	Capacity	Synology Price	Synology $/TB	3rd Party Equivalent	3rd Party Price	$/TB	% Difference
HAT3300	2TB	$84.99	$42.50	WD Red Plus 2TB	$79.99	$40.00	-5.9%
HAT3300	4TB	$99.99	$25.00	Seagate IronWolf 4TB	$84.99	$21.25	-15.0%
HAT3300	4TB	$99.99	$25.00	WD Red Plus 4TB	$99.99	$25.00	0.0%
HAT3300	6TB	$149.99	$25.00	Seagate IronWolf 6TB	$139.99	$23.33	-6.7%
HAT3310	8TB	$199.99	$25.00	WD Red Plus 8TB	$179.99	$22.50	-10.0%
HAT3310	12TB	$269.99	$22.50	Seagate IronWolf 12TB	$239.99	$20.00	-11.1%

Prosumer NAS HDDs – Synology vs Seagate & WD

Synology Model	Capacity	Synology Price	Synology $/TB	3rd Party Equivalent	3rd Party Price	$/TB	% Difference
HAT5300	12TB	$449.99	$37.50	IronWolf Pro 12TB	$249.99	$20.83	-44.4%
HAT5300	16TB	$579.99	$36.25	WD Red Pro 16TB	$349.99	$21.87	-39.7%
HAT5310	20TB	$719.99	$36.00	Seagate IronWolf Pro 20TB	$399.99	$20.00	-44.4%

Enterprise SAS HDDs – Synology vs Seagate Exos

Synology Model	Capacity	Synology Price	Synology $/TB	3rd Party Equivalent	3rd Party Price	$/TB	% Difference
HAS5300	8TB	$299.99	$37.50	Seagate Exos 7E10	$259.99	$32.50	-13.3%
HAS5300	16TB	$699.99	$43.75	Seagate Exos X18	$369.99	$23.12	-47.1%
HAS5310	20TB	$829.99	$41.50	Exos X20	$499.99	$25.00	-39.8%

Enterprise SATA SSDs – Synology vs Kingston

Synology Model	Capacity	Synology Price	Synology $/TB	3rd Party Equivalent	3rd Party Price	$/TB	% Difference
SAT5221	480GB	$169.99	$354.15	Kingston DC600M	$102.99	$214.56	-39.4%
SAT5221	3.84TB	$979.99	$255.21	Kingston DC600M	$522.99	$136.20	-46.6%
SAT5210	7TB	$1859.99	$265.71	Kingston DC600M (7.68TB)	$955.99	$124.48	-48.6%

NVMe SSDs – Synology vs WD Red SN700

Synology Model	Capacity	Synology Price	Synology $/TB	3rd Party Equivalent	3rd Party Price	$/TB	% Difference
SNV3410	800GB	$269.99	$337.49	WD Red SN700 1TB	$139.99	$139.99	-48.1%
SNV3510	800GB	$299.99	$374.99	WD Red SN700 1TB	$139.99	$139.99	-53.3%

In short, while Synology’s drives are built on reputable platforms and do offer advantages like verified DSM integration and predictable firmware behavior, the value proposition becomes questionable—especially in higher capacities and enterprise deployments. For many users, especially SMBs and home power users deploying multi-drive setups, that extra 40–50% markup can be hard to justify. When the mechanical hardware is near-identical and the only major differentiator is firmware control, it’s no wonder many are pushing back against this pricing structure.)

SYNOLOGY DSM Storage Manager Benchmarks (1st and 3rd Party Drive Media)

Zoom in to see the results. IMPORTANT that you keep in mind that these SSDs and HDDs are different capacities and therefore direct comparison and correlation between their performance is not fair – I include these because I think it is important to compare the general gist of using Synology HDD media in a system and then alternatives, but measured with Synology’s in-system tools. Larger capacities mostly tend to yeald better results in any brand of drive (not a ‘do-or-die’ rule, but generally true).

SYNOLOGY HAT3300 HDD	Seagate Ironwolf HDD
SYNOLOGY HAT5300 HDD	Seagate EXOS HDD
SYNOLOGY SAT5200 SSD	Kingston DC600 SATA SSD
SYNOLOGY M.2 NVMe SSD	TeamGroup T-Create Gen3 M.2 SSD

Synology Hard Drives and SSDs vs Seagate, WD, etc – Performance

IMPORTANT – In the process of upscaling the test result images (as there is a lot crammed in, so I have included the slightly blurred ones here) but I and will replace these with upscaled versions as soon as possible.

When it comes to performance, Synology’s hard drives and SSDs generally stay within expected ranges for their class—but with some caveats. Most of their HDDs mirror the performance of the OEM drives they’re based on, particularly in the HAT3300 and HAT3310 lines, which perform nearly identically to WD Red Plus and Seagate IronWolf models. You’re looking at familiar specs here: 5400–7200 RPM spin speeds, ~200–280MB/s sequential transfer rates, and ~180TB/yr workload ratings. That’s no surprise, considering these are essentially Seagate or Toshiba drives with Synology firmware and branding. Where things start to scale up, like in the HAT5300 and HAS5300 series, the specs remain on par with their higher-end third-party equivalents. These drives offer 550TB/year workloads, 7200 RPM motors, and MTBF figures around 2.5 million hours—just like IronWolf Pro, WD Red Pro, or Seagate Exos. But Synology currently tops out at 20TB in both SATA and SAS drives, while the competition is already pushing 22TB, 24TB, and even 26TB models. So, if you’re planning a high-capacity build, Synology might already be limiting your options on sheer scale alone.

NAS HDDs – Capacity, Performance, Endurance & Class Comparison

Model	Capacity Range	Max Transfer Rate	Spindle Speed	Workload	MTBF	Class
Synology HAT3300	2–6TB	202 MB/s	5400/7200 RPM	180 TB/yr	1M hrs	Entry NAS
WD Red Plus	2–14TB	260 MB/s	5400/7200 RPM	180 TB/yr	1M hrs	Entry NAS
Seagate IronWolf	2–12TB	210 MB/s	5400/7200 RPM	180 TB/yr	1M hrs	Entry NAS
Synology HAT3310	8–16TB	281 MB/s	7200 RPM	180 TB/yr	1M hrs	Entry NAS
Synology HAT5300	4–20TB	281 MB/s	7200 RPM	550 TB/yr	2.5M hrs	Prosumer
IronWolf Pro	2–24TB	285 MB/s	7200 RPM	550 TB/yr	2.5M hrs	Prosumer
WD Red Pro	2–26TB	287 MB/s	7200 RPM	550 TB/yr	2.5M hrs	Prosumer
Synology HAS5300	8–20TB	281 MB/s	7200 RPM	550 TB/yr	2.5M hrs	Enterprise SAS
Seagate Exos	12–24TB	285 MB/s	7200 RPM	550 TB/yr	2.5M hrs	Enterprise SAS

Performance parity continues with Synology’s SATA SSDs. The SAT5221 and SAT5210 series are very close in spec to Kingston’s DC600M drives, offering similar read/write speeds, IOPS performance, and endurance levels. The SAT5210 even pushes into ultra-DWPD territory, boasting up to 10,000 TBW and higher daily write thresholds, which is competitive in the enterprise space. If you need high write endurance and steady power loss protection, these drives tick the right boxes.

The gap, however, opens up in the NVMe tier. Synology’s SNV3400 and SNV3500 drives fall short compared to third-party NVMe SSDs like the WD Red SN700. While Synology focuses on endurance, PLP (power loss protection), and integration with DSM caching features, the performance ceiling on these drives is noticeably lower—both in terms of sequential throughput and IOPS. Capacities also top out at 800GB, while others offer 1TB and beyond with faster read/write performance. So if you’re after speed or larger NVMe caching pools, Synology’s current options may feel behind the curve.

SATA & NVMe SSDs – Synology vs Kingston

In short, Synology’s drives generally deliver solid, reliable performance that matches their third-party foundations—but the benefits of full DSM compatibility come with a trade-off. While the SATA range holds its ground, the NVMe lineup is due for an update if Synology wants to stay competitive against higher-capacity, higher-speed SSDs now widely available elsewhere. If performance is your main concern, particularly for NVMe caching or flash-heavy tasks, third-party options may be a better fit unless full integration is a must-have.

Synology Hard Drives and SSDs Guide – The Good and the Bad

In reviewing Synology’s lineup of hard drives and SSDs, it’s clear that the hardware itself is solid—built on trusted OEM foundations and tuned to work seamlessly within DSM environments. From a compatibility and reliability standpoint, these drives do offer advantages, particularly for users who want an integrated, no-hassle deployment. That said, these benefits come with notable trade-offs. In many cases, Synology’s drives are mechanically identical to models from Seagate, Toshiba, or Phison, yet priced significantly higher—especially in the enterprise and NVMe tiers. While some of that premium may be justified by firmware-level integration, PLP, or simplified support paths, the cost disparity is hard to ignore for experienced users already comfortable with third-party hardware.

Ultimately, the decision to adopt Synology-branded drives will depend on your priorities. If you’re building a system where out-of-the-box compatibility, long-term support, and unified ecosystem control are paramount, Synology’s media may be a safe bet—albeit at a higher packaged price. But if your focus is on maximizing performance per dollar, scaling capacity, or customizing your setup beyond Synology’s verified list, third-party alternatives remain the more flexible and cost-effective choice. Until Synology expands their verified media list and adjusts regional pricing or availability, many users will continue to see these drives not as a value-add, but as an imposed requirement.

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What Are Synology NAS Product Refreshes and What is Synology’s Logic?

When Synology introduces a new wave of NAS devices, it’s easy to assume that each new model is a significant leap forward. However, many of these launches are better classified as product refreshes, not entirely new product lines. This distinction matters. A refresh typically reuses a core hardware platform—such as the chassis, CPU, or layout—but includes modest updates like better network interfaces, more memory, or small component shifts. In 2025, Synology rolled out one of its broadest refresh cycles in years, affecting models across their two-bay, four-bay, five-bay, and eight-bay portfolios. Understanding what a refresh actually is helps users make more informed decisions, especially when evaluating whether to upgrade or wait.

Synology refreshes its products for a few practical reasons. First, component availability and pricing change over time. CPUs and other hardware elements that were once expensive or reserved for high-tier models often become more affordable, making them suitable for use in lower-tier devices. For example, the AMD V1500B processor, once exclusive to mid-tier and enterprise NAS systems, has trickled down into several 2025 refreshes like the DS925+ and DS1525+. Similarly, market-wide transitions—such as the shift from 1GbE to 2.5GbE—are reflected in these updates, allowing Synology to modernize existing models while keeping their manufacturing costs and prices relatively stable.

One of the key things that sets a refresh apart from a brand-new NAS model is Synology’s commitment to product tier consistency. Devices like the DS725+, DS425+, or DS1825+ aren’t being built to reinvent the wheel. Instead, they exist to preserve the price-to-performance balance that their predecessors established in the Synology product lineup. By holding onto the same CPU, expanding RAM slightly, and upgrading network ports from 1GbE to 2.5GbE, Synology keeps these NAS solutions within their traditional target audience—be it home users, prosumers, or small businesses. The physical design and key feature sets are familiar, and that’s deliberate. Refreshes aim to improve what already works, not redefine the category.

It’s also worth recognizing that Synology’s product refreshes are not aimed at recent buyers. If you just picked up a DS723+ or DS923+ last year, you are not the intended audience for the DS725+ or DS925+. Instead, these refreshes are aimed at users still running a DS216+, DS416, or DS1813+—users who are five to ten years deep into their existing systems. For them, the new hardware represents a meaningful leap forward, even if it looks modest on paper. When you compare a DS916+ to a DS925+, the differences in memory, CPU threads, M.2 caching, and DSM features become much more pronounced.

Pricing also plays a central role in Synology’s refresh strategy. For the most part, Synology tries to keep prices stable across generations, despite inflation and rising manufacturing costs. For example, the DS425+ and DS225+ refreshes, though modest in their hardware upgrades (mainly 2.5GbE LAN replacing 1GbE), still aim to hit the same price points as their DS423+ and DS224+ predecessors. This can make refreshes seem less appealing to new buyers comparing specs on a chart, but it serves long-term users who value Synology’s software ecosystem, consistent performance, and extended support.

One notable outlier in Synology’s refresh strategy is the continued use of the Intel Celeron J4125 processor, particularly in models like the DS425+, DS225+, and DS625slim. Despite Synology’s tendency to update hardware every 2–3 years based on market trends and component availability, the J4125—originally launched in 2019—feels increasingly outdated in 2025. Intel itself has moved away from the Celeron/J-series naming convention entirely, transitioning to more efficient and capable platforms like Alder Lake-N and N-series processors. This shift highlights just how long in the tooth the J4125 has become. With no support for newer instruction sets, lower efficiency compared to modern equivalents, and limited future compatibility, its continued presence in refreshed Synology NAS models stands in stark contrast to the broader trend of hardware advancement. While Synology has prioritized price consistency and DSM support, the persistence of this older CPU dampens the appeal of these refreshes for new buyers who expect more current internals at a similar price point.

Another important factor is Synology’s software-first development model. Their NAS hardware isn’t meant to push technical limits but rather serve as a stable, reliable platform for DSM (DiskStation Manager). That’s why even in refreshes, the focus is on compatibility and long-term support over flashy specs. Synology has made this clear through product cycles like the DS1825+, which retains the same CPU as the DS1821+ but gains 2.5GbE and better memory configuration—supporting the increasing demands of DSM applications without needing an overhaul of the entire system.

In summary, a product refresh in Synology’s ecosystem is not a groundbreaking redesign, but a thoughtful, incremental update within an established product profile. These refreshes ensure the long-term viability of key NAS tiers while adapting to evolving market standards like 2.5GbE, more demanding software workloads, or new expansion options. For long-time users, they offer an accessible upgrade path. For newcomers, they may seem underwhelming on paper. But in either case, they represent a balancing act between hardware, price, and software synergy, which has long been Synology’s model—whether you agree with it or not.

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Synology DS1825+ vs DS1821+ NAS Comparison – Get It Right, FIRST TIME!

When Synology releases a new NAS in its “Plus” lineup, users often expect a blend of practical improvements, long-term support, and a reasonable upgrade path from the previous generation. The Synology DS1825+ arrives in 2025 as the official successor to the 2020/2021-released DS1821+, carrying over much of the same core design while introducing selective enhancements—and a few contentious changes. Both are 8-bay desktop NAS systems targeted at advanced home users, small businesses, and content creators who need multi-user access, flexible RAID configurations, and extensive app support. However, while the DS1821+ was praised for its broad compatibility and modular connectivity, the DS1825+ adopts a more tightly controlled hardware ecosystem. In this comparison, we break down the key differences across hardware, ports, storage capabilities, DSM software features, and drive compatibility so you can decide which model truly fits your long-term needs—without second-guessing your choice later.

Synology DS1825+ vs DS1821+ NAS Comparison – Internal Hardware

At the center of both the Synology DS1821+ and DS1825+ is the AMD Ryzen V1500B processor, a 4-core, 8-thread embedded SoC with a 64-bit architecture and a base frequency of 2.2 GHz. This chip, built on the Zen architecture, offers a balance of power efficiency and multi-threaded performance suited for environments with simultaneous multi-user file access, virtual machines, and complex RAID configurations. Synology’s decision to retain the same processor in the DS1825+ reflects confidence in its reliability and capability. However, for users hoping for a jump to Zen 2 or Zen 3-based hardware, the lack of a CPU upgrade could be a disappointment—especially considering that competing vendors have started adopting newer architectures for their mid-range systems. Still, for typical NAS tasks that do not involve on-the-fly 4K video transcoding or GPU-heavy operations, the V1500B remains a stable and effective platform with AES-NI encryption support and virtualization compatibility across VMware, Hyper-V, and Docker workloads.

Thermal and power characteristics between the two systems remain largely consistent, with both featuring dual 120mm fans and an internal 250W PSU that can handle full drive loads with expansion units attached. The DS1821+ and DS1825+ are also nearly identical in physical size and structure, though the newer model has a slightly higher idle noise level—23.8 dB(A) versus 22.2 dB(A)—due to denser internal configuration and possibly fan speed curve adjustments. From an operational standpoint, the DS1825+ is marginally more power-efficient in idle states, consuming just 18.34W during HDD hibernation compared to 26.18W in the DS1821+. These marginal differences suggest a refinement in system tuning, although not a radical redesign. Overall, while the DS1825+ doesn’t revolutionize internal hardware, its doubled memory and subtle optimizations give it the edge for users planning to push DSM with multiple services or those who prefer an upgrade-free deployment experience.

Synology DS1825+ vs DS1821+ NAS Comparison – Ports and Connections

One of the most tangible areas of differentiation between the DS1821+ and DS1825+ lies in their external connectivity. The older DS1821+ is equipped with four 1GbE RJ-45 LAN ports, a familiar configuration that supports link aggregation and network redundancy. This setup was common in Synology’s mid-range lineup during its 2020–2022 releases, offering a total aggregated bandwidth of up to 4Gbps—assuming your switch infrastructure supports it. For many small business users, this array of ports provided simple flexibility: you could dedicate individual ports for different services or bond them for faster file transfers. However, in practice, 1GbE is increasingly becoming a limiting factor for modern workloads, especially in environments with large raw video files, database access, or multiple users performing high-speed backups.

Beyond networking, the DS1825+ introduces a notable change in expansion port design. The DS1821+ includes two eSATA ports for attaching Synology DX517 expansion units, which align with legacy expansion practices. In contrast, the DS1825+ replaces these with two USB-C-based expansion ports, designed specifically for use with the newer DX525 expansion units. While this doesn’t directly affect day-to-day operations, it signals a move toward a USB-based proprietary interface for future expansion, likely with more streamlined cabling and higher throughput potential. Additionally, the DS1825+ trims down from four USB 3.2 Gen 1 ports to three, a minor trade-off that may impact users with multiple USB-connected devices such as UPS units or backup drives. Still, for most users, the improved network and expansion standards make the DS1825+ more forward-looking, even if it reduces legacy connectivity options found on the DS1821+.

Synology DS1825+ vs DS1821+ NAS Comparison – Storage

Both the DS1821+ and DS1825+ offer eight front-facing SATA drive bays, supporting 3.5″ HDDs and 2.5″ SSDs, with hot-swappable trays for easy maintenance and upgrades. On the surface, storage capacity and configuration appear nearly identical: both models can scale up to 18 total drives using two Synology expansion units and support RAID levels including SHR, RAID 5, 6, and 10. This makes either system a viable choice for users with large datasets, whether for media, surveillance, or business-critical file hosting. However, subtle distinctions in how storage can be configured and expanded in each model make a significant difference over time.

Storage Feature	Synology DS1821+	Synology DS1825+
Drive Bays	8 × 3.5″/2.5″ SATA (hot-swappable)	8 × 3.5″/2.5″ SATA (hot-swappable)
Max Drive Bays (with Expansion)	18 (via 2 × DX517)	18 (via 2 × DX525)
M.2 NVMe Slots	2 × M.2 2280 (cache only, 3rd-party SSDs allowed)	2 × M.2 2280 (cache or storage pools, Synology-only SSDs)
Max Single Volume Size	108 TB	200 TB (requires 32 GB RAM)
Max Internal Volumes	64	32
Supported RAID Types	SHR, JBOD, RAID 0, 1, 5, 6, 10	SHR, JBOD, RAID 0, 1, 5, 6, 10
Third-Party HDD/SSD Support	Fully supported (with warnings)	Blocked at install/init if not verified
Storage Pool Creation with Unverified Drives	Allowed	Blocked
Storage Pool Expansion (Unverified Drives)	Supported	Blocked
RAID Recovery with Unverified Drives	Supported	Blocked
Hot Spare (Unverified Drives)	Supported	Blocked
Storage Manager Behavior (Unverified Drives)	Warnings shown, but system fully functional	Persistent alerts, some functions disabled

The DS1825+ supports storage pools using its two internal M.2 NVMe slots, something the DS1821+ does not. On the older model, those slots are limited strictly to SSD caching, and even then, Synology allowed users to use third-party NVMe drives for read/write acceleration. In the DS1825+, Synology enables users to form full storage pools using M.2 SSDs—but only if those SSDs are from Synology’s own SNV3400 or SNV3410 series. This adds flexibility in theory, especially for users interested in all-flash configurations or high-speed tiers, but restricts user choice in practice. The DS1821+ offers more freedom in selecting SSDs and hard drives, with only non-blocking warning messages when using unverified models, while the DS1825+ actively blocks storage pool creation and system initialization with unlisted drives.

This tightening of compatibility extends into pool expansion, RAID rebuilds, and even hot spare assignments. In the DS1821+, users could freely mix third-party drives and expand pools over time using available or similarly specced HDDs—even those not on the official compatibility list. The DS1825+ takes a stricter approach: attempts to initialize DSM with unverified HDDs will fail, and pool expansion or RAID recovery with unsupported drives is outright blocked. While existing volumes from older NAS systems can still be migrated and booted, they will trigger persistent compatibility warnings in DSM, often with degraded system health indicators. This shift may offer Synology more control over performance validation and support consistency, but it limits flexibility for users relying on diverse or existing storage media—making the DS1821+ a better option for those with a mix-and-match approach, and the DS1825+ more suitable for fully standardized Synology deployments.

Synology DS1825+ vs DS1821+ NAS Comparison – DSM Capabilities

Both the DS1821+ and DS1825+ are powered by Synology’s DiskStation Manager (DSM) 7.2 operating system, offering access to a rich suite of applications for file management, backup, surveillance, virtualization, and cloud syncing. Core tools such as Synology Drive and Synology Photos provide a private cloud alternative to services like Google Drive or Dropbox, while packages like Hyper Backup and Active Backup for Business enable full-system and client-based data protection strategies. These services run similarly on both systems, but hardware differences can influence practical performance. For example, the DS1825+ ships with 8 GB of ECC memory by default, making it more responsive when running multiple DSM apps in parallel—such as Snapshot Replication combined with Virtual Machine Manager and Drive Client Sync. In contrast, the DS1821+ ships with 4 GB of memory, which may require an upgrade before achieving similar multitasking fluidity, especially in environments with more than a few simultaneous users.

DSM Feature / Capability	Synology DS1821+	Synology DS1825+
DSM Version	DSM 7.2+	DSM 7.2+
Max Internal Volumes	64	32 ▼ Reduced
Max Single Volume Size	108 TB	200 TB (requires 32 GB RAM) ▲ Increased
Snapshot Replication	256 per shared folder / 4,096 total system snapshots	256 per shared folder / 4,096 total system snapshots
Virtual Machine Manager (VMM)	Up to 8 VM / Virtual DSM instances	Up to 8 VM / Virtual DSM instances
Surveillance Station	Up to 40 cameras / 4K / 1,200 FPS (H.265)	Up to 40 cameras / 4K / 1,200 FPS (H.265)
Synology Drive Users	Up to 110 users ▲ Higher	Up to 100 users ▼ Lower
Synology Office Users	Up to 110 concurrent users ▲ Higher	Up to 100 concurrent users ▼ Lower
Hybrid Share Folder Support	10	10
High Availability Support	Yes	Yes
RAID Recovery (with unverified drives)	Supported	Blocked
Hot Spare / Expansion (unverified drives)	Supported	Blocked
Storage Manager (Unverified Drives)	Warnings only, system fully functional	Persistent alerts, functions blocked
M.2 NVMe Storage Pools	Not supported	Supported (Synology NVMe SSDs only)
M.2 NVMe Caching with 3rd-party SSDs	Supported	Blocked
Protocols Supported	SMB1/2/3, NFSv3/v4, FTP, WebDAV, Rsync, iSCSI, HTTP/HTTPS, LDAP	SMB1/2/3, NFSv3/v4, FTP, WebDAV, Rsync, iSCSI, HTTP/HTTPS, LDAP

Differences emerge in how each system handles volume structure and scaling. The DS1821+ supports up to 64 internal volumes, giving it an advantage in deployments where users need to segregate workloads—for instance, separating surveillance footage, shared team folders, user home directories, and VM storage into distinct volumes for quota management and performance tuning. This flexibility makes the DS1821+ better suited for educational institutions or small business IT teams who manage multiple user groups and need clear storage separation. The DS1825+, on the other hand, limits internal volumes to 32 but increases the maximum single-volume size to 200 TB (with 32 GB RAM installed). This makes it better aligned with large, contiguous workloads like uncompressed 4K video editing archives, security footage retention for legal compliance, or massive CAD/CAM datasets—all of which benefit more from fewer, larger volumes than from numerous smaller ones.

Service limits within DSM also subtly differentiate the two models. The DS1821+ is rated for up to 110 concurrent users in Synology Drive and Office, whereas the DS1825+ recommends a slightly lower threshold of 100 users. While the difference is marginal, it may reflect the DS1825+’s tighter memory tuning or more restrictive compatibility model, which now relies on verified Synology storage media for optimal performance. For example, in environments running Synology Office with real-time collaborative editing—paired with Drive, MailPlus, and external file sharing through WebDAV—the DS1821+ might offer more flexibility when loaded with third-party high-performance SSDs for caching. The DS1825+, restricted to Synology’s own SNV3400/3410 NVMe drives, demands tighter ecosystem compliance, which could affect responsiveness if storage performance becomes a bottleneck. Nonetheless, both models offer full support for advanced DSM modules like Synology High Availability, SAN Manager, and Hybrid Share, ensuring that users deploying in mission-critical environments still have access to the high-availability and hybrid cloud features that define Synology’s enterprise-ready platform.

Synology DS1825+ vs DS1821+ NAS Comparison – Conclusion

Choosing between the Synology DS1825+ and DS1821+ comes down to whether you prioritize modern hardware refinements or broader long-term flexibility. The DS1825+ introduces subtle but meaningful upgrades: faster 2.5GbE connectivity, double the base memory, and NVMe storage pool support—features that clearly position it as the more forward-thinking choice for users committed to staying within the Synology ecosystem. However, these improvements come with tighter restrictions, most notably in its rigid drive compatibility policy. DSM cannot be installed unless only Synology-verified drives are used, and the system actively blocks unverified drives from being used in storage pools, RAID rebuilds, or even hot spare configurations. In contrast, the DS1821+ offers more freedom—supporting a wider range of HDDs and SSDs, allowing RAID recovery and expansion with non-Synology drives, and presenting a cleaner, less obstructive DSM experience when migrating from older hardware. While it may lack the newer model’s out-of-the-box performance gains, its open-ended architecture gives users—especially those with legacy drives or mixed environments—more breathing room. For users building a NAS from scratch and willing to adopt Synology’s closed hardware ecosystem, the DS1825+ is a capable and streamlined solution. But for those looking to extend the life of existing hardware or retain control over their storage media choices, the DS1821+ remains the more versatile and user-friendly option.

Aspect	Synology DS1821+	Synology DS1825+
Pros	– Full support for 3rd-party drives (HDDs & SSDs)	– Higher default RAM (8 GB ECC pre-installed)
	– Supports RAID recovery, expansion, and hot spares with unverified drives	– 2.5GbE networking (faster out-of-the-box performance)
	– More flexible for DIY and legacy system migrations	– NVMe storage pool support (Synology SSDs only)
	– Supports more internal volumes (up to 64)	– USB-C expansion ports with newer DX525 units
	– Better choice for mixed-brand or cost-conscious deployments	– Improved volume scaling (up to 200TB per volume with RAM upgrade)
Cons	– Older network setup (1GbE x4, slower unless aggregated)	– Strict drive compatibility enforcement (Synology-only drives required)
	– No NVMe storage pool support	– Blocks DSM install with unverified drives
	– Lower default memory (4 GB, upgrade likely needed for advanced workloads)	– Fewer internal volumes supported (32 max)
		– Persistent system warnings when migrating existing arrays with non-Synology drives
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Synology DS1525+ vs DS1522+ NAS Comparison – Get It Right, FIRST TIME!

With the arrival of the Synology DS1525+ in 2025, many users are now weighing it against its immediate predecessor, the DS1522+, released in 2022. On the surface, both NAS units share the same 5-bay form factor, nearly identical chassis design, and very similar price points—typically between $699 and $799 at launch. However, a deeper dive reveals a number of meaningful changes in hardware resources, storage expansion policies, and how Synology now handles drive compatibility and system flexibility. While the DS1525+ does offer better networking and CPU core count, it also introduces tighter restrictions on what drives can be used, how storage pools are formed, and what options are available to users looking to migrate data from older systems. By contrast, the DS1522+ retains a far more open approach to hardware, offering greater freedom for enthusiasts and IT professionals. In this article, we’ll break down the internal hardware, ports, storage support, DSM software capabilities, and system behavior of these two NAS systems—giving you the context you need to make the right decision the first time, and avoid buyer’s regret later.

Synology DS1525+ vs DS1522+ NAS Comparison – Internal Hardware

The most noticeable hardware difference between the DS1525+ and DS1522+ lies in their processors. The DS1522+ is powered by a dual-core AMD Ryzen R1600 CPU, which operates at a base frequency of 2.6 GHz and can boost up to 3.1 GHz. This chip delivers strong single-threaded performance and is very power efficient, making it well-suited for environments where tasks are sequential or lightly parallelized—such as SMB file sharing, surveillance, or general-purpose storage. The DS1525+, in contrast, uses a quad-core AMD Ryzen V1500B processor running at a fixed 2.2 GHz. While it lacks boost frequency, the additional cores and threads make it the more capable option for multitasking-intensive DSM deployments. Workloads like hosting multiple Docker containers, running several VMs, or operating high-volume backup jobs are handled more smoothly by the V1500B thanks to its stronger concurrent throughput. While synthetic benchmarks might show the R1600 ahead in single-threaded operations, in day-to-day NAS usage, the V1500B’s multitasking benefits are more relevant—particularly for users aiming to centralize many services on one box.

Synology DS1525+ vs DS1522+ NAS Comparison – Ports and Connections

The differences between the DS1525+ and DS1522+ become more apparent when examining their networking and expansion connectivity. The DS1522+ is equipped with four 1GbE RJ-45 LAN ports, which support link aggregation for up to 4 Gbps combined bandwidth when used with a managed switch. This configuration provides solid redundancy and flexible port allocation, especially for environments where isolating traffic across different services (e.g., backups, media, surveillance) is desirable. However, in 2024 and beyond, 1GbE is increasingly viewed as a bottleneck—particularly for users working with 4K video editing, large VM images, or fast local backups. The DS1525+ addresses this issue by shifting to 2 × 2.5GbE RJ-45 LAN ports, allowing up to 5 Gbps total bandwidth through link aggregation, and faster speeds on a per-connection basis, even when using unmanaged 2.5GbE switches that are now more common and affordable. This change aligns the DS1525+ with modern mid-tier NAS expectations and offers improved real-world performance, especially for multi-user workloads and high-speed transfers from SSD caches or NVMe pools.

Feature	Synology DS1522+	Synology DS1525+
LAN Ports	4 × 1GbE RJ-45	2 × 2.5GbE RJ-45
Link Aggregation / Failover	Yes	Yes
USB Ports	2 × USB 3.2 Gen 1	2 × USB 3.2 Gen 1
Expansion Ports	2 × eSATA (for DX517)	2 × USB Type-C (for DX525)
PCIe Slot	1 × PCIe Gen3 x2 (for 10GbE upgrade)	1 × PCIe Gen3 x2 (for 10GbE upgrade)
Wake on LAN / WAN	Yes	Yes
Scheduled Power On / Off	Yes	Yes
Hot-Swappable Drive Bays	5 × SATA HDD/SSD (M.2 not hot-swappable)	5 × SATA HDD/SSD (M.2 not hot-swappable)
M.2 NVMe Slots	2 × M.2 2280 (cache only, 3rd-party SSDs supported)	2 × M.2 2280 (cache and storage, Synology SSDs only)
Expansion Compatibility	DX517 (eSATA interface)	DX525 (USB-C interface)

In terms of USB connectivity, both models include two USB 3.2 Gen 1 ports, suitable for attaching external drives, UPS units, or compatible USB printers. These ports remain unchanged between models and offer no direct performance advantage to either system. Where the expansion capability does change significantly is in the port type for connecting additional storage enclosures. The DS1522+ includes two eSATA ports, allowing it to connect up to two DX517 expansion units, adding 10 more drive bays. The DS1525+, however, replaces these with two USB Type-C expansion ports, which interface with the newer DX525 expansion units. While the overall expansion capacity remains the same (15 total bays), the move to USB-C reflects a generational shift in Synology’s design language. USB-C may offer slightly more flexible cable routing and future-proofing, but it also introduces a hard cutoff between older and newer ecosystems. For users with existing DX517s or other eSATA-based gear, this limits backwards compatibility and locks the DS1525+ into the latest hardware infrastructure.

Additionally, both units include a PCIe Gen3 x2 slot for optional 10GbE network upgrades. Synology’s E10G22-T1-Mini card is supported on both models and provides a compact, cost-effective way to future-proof network performance. However, given the DS1525+ already starts with 2.5GbE, users may find less urgency to upgrade immediately compared to the DS1522+, where a 10GbE card may be needed sooner to break past 1GbE limitations. Both models support Wake-on-LAN and scheduled power events, and both feature dual rear fans for effective cooling regardless of network traffic or drive load. From a connectivity standpoint, the DS1525+ represents a forward step toward higher-speed networking and modern expansion methods—but it does so at the cost of legacy compatibility, which may matter for users with established infrastructure. In contrast, the DS1522+ offers broader port coverage and flexibility but risks becoming dated more quickly in high-throughput environments.

Synology DS1525+ vs DS1522+ NAS Comparison – Storage

At first glance, storage capacity and physical layout appear virtually identical between the DS1525+ and DS1522+. Both systems offer five main drive bays that support 3.5″ SATA HDDs and 2.5″ SATA SSDs, as well as two M.2 NVMe SSD slots for caching or, in the case of the DS1525+, full storage pool creation. Each NAS can be expanded up to a total of 15 bays using two proprietary Synology expansion units (DX517 for the DS1522+, DX525 for the DS1525+), enabling up to 240 TB of raw storage assuming maximum capacity drives. However, a major divergence emerges when we examine drive compatibility policies. The DS1522+ follows Synology’s older, more permissive approach: users may install third-party drives from brands like Seagate, Western Digital, or Toshiba with only warning messages shown during setup. Storage pools, RAID arrays, and DSM installation all proceed without functional restrictions, making it a flexible platform for users with existing drives or cost-sensitive deployments.

Storage Feature	Synology DS1522+	Synology DS1525+
Drive Bays	5 × 3.5″/2.5″ SATA HDD/SSD (Hot-swappable)	5 × 3.5″/2.5″ SATA HDD/SSD (Hot-swappable)
M.2 NVMe Slots	2 × M.2 2280 (Cache only, 3rd-party SSDs allowed)	2 × M.2 2280 (Cache & Storage Pool, Synology SSDs only)
Maximum Drive Bays (with Expansion)	15 (with 2 × DX517 via eSATA)	15 (with 2 × DX525 via USB-C)
Supported RAID Types	SHR, Basic, JBOD, RAID 0/1/5/6/10	SHR, Basic, JBOD, RAID 0/1/5/6/10
Max Internal Volumes	64	32
Max Volume Size	108 TB	200 TB (requires 32 GB RAM)
NVMe Storage Pool Support	Not supported	Supported (Synology SNV drives only)
3rd-Party Drive Support	Fully supported (with warnings)	Blocked (DSM install/expansion/recovery restricted)
RAID Recovery with Unverified Drives	Supported	Not allowed
Storage Pool Expansion (Unverified)	Supported	Blocked
Hot Spare Assignment (Unverified)	Supported	Blocked
Drive Migration (with 3rd-party drives)	Functional, with warnings	Allowed, but persistent warnings & blocked expansion

The DS1525+, by contrast, enforces the strict drive verification policy introduced in Synology’s newer Plus series models, like the DS925+ and DS1825+. At launch, only Synology-branded drives (HAT3300, HAT5300, SAT5200, and SNV3400 series) are listed as officially compatible. If users attempt to initialize DSM using unverified HDDs—such as a standard WD Red Plus or Seagate IronWolf—the installation process will be blocked entirely. This represents a significant limitation for long-time Synology users who are accustomed to broader hardware flexibility. Even after successful DSM setup, the system will not allow users to expand storage pools, rebuild degraded RAID arrays, or assign hot spares using non-verified drives. Persistent warnings and degraded status indicators in Storage Manager will appear even for migrated volumes, making the DS1525+ less accommodating for mixed-media configurations or DIY upgrades. SATA SSDs, while slightly more flexible in some scenarios, are still subject to similar warning behaviors post-install.

Further separating the two models is support for NVMe-based storage pools. The DS1522+ only allows M.2 NVMe SSDs to be used for read/write caching, and it permits the use of third-party SSDs for this function, giving users a cost-effective route to performance acceleration. The DS1525+, however, allows these NVMe slots to be used for full DSM storage volumes—but only when using Synology-verified SNV-series SSDs. This enables the creation of fast, low-latency storage pools using NVMe media, which is a compelling advantage for certain workflows (like media scratch disks or high-speed sync folders). Still, the restricted compatibility policy limits practical utility for those who already own quality NVMe drives from other vendors. In short, while the DS1525+ technically offers more advanced storage architecture, the DS1522+ offers far more freedom, especially for users managing legacy systems, migrating data from older Synology devices, or sourcing their own HDDs and SSDs independently.

Synology DS1525+ vs DS1522+ NAS Comparison – DSM Capabilities

Both the DS1525+ and DS1522+ run Synology’s DSM 7.2 operating system and provide access to the same broad library of official and third-party packages. This includes core applications such as Synology Drive for file sync and access, Synology Office for collaborative documents, and Active Backup for Business for system-wide backup management. The app experience is largely identical on both devices, with support for Virtual Machine Manager, Hyper Backup, Snapshot Replication, Synology Photos, and Surveillance Station. However, the differences in system hardware and compatibility enforcement subtly influence how DSM behaves and what features remain available under different configurations. For example, both models support up to 256 snapshots per shared folder and a system-wide maximum of 4,096 snapshots, but users on the DS1525+ will be subject to stricter compatibility enforcement in DSM’s Storage Manager if using drives that aren’t on Synology’s approved list.

DSM Feature / Capability	Synology DS1522+	Synology DS1525+
DSM Version	DSM 7.2+	DSM 7.2+
Max Internal Volumes	64	32 ▼
Max Single Volume Size	108 TB	200 TB (requires 32 GB RAM) ▲
Snapshot Replication	256 per shared folder / 4,096 total system snapshots	256 per shared folder / 4,096 total system snapshots
Synology Drive Users	Up to 60	Up to 80 ▲
Synology Office Users	Up to 60	Up to 80 ▲
Virtual Machine Manager (VMs)	Up to 4 Virtual Machines	Up to 8 Virtual Machines ▲
Virtual DSM Instances (Licensed)	Up to 4	Up to 8 (1 free license) ▲
Hybrid Share Folder Limit	10	10
Surveillance Station (H.265)	40 cameras / up to 1200 FPS	40 cameras / up to 1200 FPS
Maximum SMB Connections (RAM Expanded)	30	40 ▲
RAID Recovery with 3rd-Party Drives	Supported	Blocked
Storage Expansion with Unverified Drives	Supported	Blocked
Hot Spare (Unverified Drives)	Supported	Blocked
M.2 NVMe Caching (3rd-Party SSDs)	Supported	Blocked
NVMe Storage Pool Creation	Not supported	Supported (Synology SNV SSDs only)
DSM Storage Manager Behavior (Unverified)	Warnings only, all features functional	Persistent alerts, blocks expansions and rebuilds
High Availability Support	Yes	Yes
Full System Backup (Hyper Backup)	Yes (DSM 7.2+)	Yes (DSM 7.2+)

Where this becomes particularly relevant is during system migration or advanced storage scenarios. The DS1522+ handles drive migration and unverified HDDs without functional limitation. DSM will display minor warnings but still permit RAID recovery, storage pool expansion, hot spare assignments, and cache creation—even with mixed-brand hardware. By contrast, the DS1525+ introduces active blocks within DSM for unsupported drives. Users migrating from older Synology NAS devices using drives like WD Red Plus or Seagate IronWolf will find that, while the DS1525+ may import the pool, DSM will flag the drives as unverified and prevent future RAID rebuilds or expansions unless all disks are from Synology’s supported list. These alerts cannot be disabled, and they will persist across the user interface, making the system appear at risk even if the drives themselves are healthy. This creates a significant difference in administrative experience, especially for IT professionals managing multiple systems or resellers integrating legacy hardware.

In terms of user and service scalability, the DS1525+ supports slightly higher limits overall. It allows for up to 80 Synology Drive users and Office users (versus 60 each on the DS1522+) and can support up to 8 concurrent virtual machines versus 4 on the DS1522+, assuming sufficient RAM is installed. Surveillance Station camera and FPS limits are virtually identical, and both models support High Availability, Hybrid Share, SAN Manager, and central management features. However, the DS1525+ supports larger single volume sizes—up to 200 TB if upgraded to 32 GB RAM—compared to the DS1522+’s 108 TB ceiling. In return, the DS1522+ offers more internal volume flexibility with support for up to 64 volumes, double the DS1525+’s 32 volume limit. This trade-off reflects Synology’s shifting priorities in DSM: the DS1525+ favors fewer, denser volumes and more centralized control, while the DS1522+ gives power users finer-grained storage separation. Both systems excel with DSM, but your experience will differ depending on whether you prioritize scalability and structure—or open, hardware-flexible operation.

Synology DS1525+ vs DS1522+ NAS Comparison – Conclusion

The Synology DS1525+ and DS1522+ may look nearly identical on the outside, but they diverge sharply in philosophy, system behavior, and long-term value. The DS1522+, launched in 2022, stands as one of the last truly flexible 5-bay NAS systems in Synology’s portfolio. It offers a dual-core AMD Ryzen R1600 processor with excellent single-thread performance and supports up to 15 drives with two DX517 expansions. More importantly, it retains the traditional Synology approach to third-party drive compatibility—meaning users can install and operate a wide range of HDDs and SSDs (Seagate, WD, Toshiba, etc.) without system blocks. DSM will issue warnings if a drive isn’t officially listed, but critical features like RAID recovery, storage pool expansion, and hot spare assignment continue to function. That level of hardware openness makes the DS1522+ particularly attractive to power users, budget-conscious builders, and small IT teams looking to repurpose existing hardware. The DS1525+, released in 2025, represents a subtle but significant shift in Synology’s design strategy. On paper, it offers solid upgrades: a quad-core AMD Ryzen V1500B processor that enables better multitasking, faster 2.5GbE LAN ports for improved data throughput, lower noise and power consumption, and full NVMe storage pool support (with Synology SSDs). These improvements make the DS1525+ a better fit for users running multiple simultaneous services—such as Surveillance Station, Synology Drive, and Docker containers—all while maintaining smooth operation. However, these benefits come with stricter limitations. The unit enforces Synology’s 2025-era drive verification policy, which outright blocks DSM installation or RAID operations with unverified drives. Migration is allowed, but users will be met with persistent warnings, degraded system status indicators, and feature restrictions that can’t be bypassed. The flexibility to reuse older drives, expand arrays freely, or mix hardware brands has been systematically curtailed.

In essence, the choice between these two NAS systems reflects more than just performance—it’s a decision between openness and control. The DS1522+ remains a strong all-rounder for users who want to build their system on their own terms, manage diverse storage needs, or repurpose hardware they already trust. It’s well-suited to small businesses, creators, and experienced users who value transparency and adaptability. The DS1525+, by comparison, is more refined, but also more prescriptive. It favors users willing to commit fully to Synology’s ecosystem—those who prioritize simplicity, tighter integration, and long-term consistency, even at the expense of flexibility. It’s a better fit for turnkey environments where reliability and vendor support matter more than customization. Both NAS devices are excellent in their own right, but the right choice depends entirely on how much control you’re willing to trade for convenience—and whether your NAS should be a platform you shape, or a solution that shapes your workflow.

Aspect	Synology DS1522+	Synology DS1525+
Pros	– Broad 3rd-party HDD/SSD compatibility	– 2.5GbE LAN ports for faster networking out of the box
	– Fully supports RAID recovery, expansion, and hot spares with any drive	– NVMe SSDs can be used for storage pools (Synology SSDs only)
	– Better suited for drive migration from older NAS systems	– Quad-core CPU enables better multitasking and virtualization
	– More internal volumes supported (up to 64)	– Lower power draw and slightly quieter operation
	– Ideal for budget-conscious users and mixed-brand deployments	– Slightly higher user caps in DSM apps (Drive, Office, VMM)
Cons	– Only 1GbE networking unless upgraded	– Blocks DSM install and critical functions with unverified drives
	– No support for NVMe storage pools	– Only Synology SSDs supported for caching or NVMe volumes
	– Lower VM performance ceiling (dual-core CPU)	– Fewer internal volumes supported (32 max)
		– Less suitable for users with existing 3rd-party storage hardware
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Synology Explain WHY They Changed Drive Support and Verification in 2025 NAS

During a recent visit to Taipei for Computex 2025, I took the opportunity to visit Synology’s headquarters and speak directly with company representatives about one of the most discussed and divisive topics in the NAS community today — the company’s increasingly strict stance on hard drive compatibility. With the rollout of Synology’s latest generation of hardware, users have been met with significant limitations on the use of third-party drives, prompting concern over reduced flexibility, potential e-waste, and the future direction of Synology’s hardware ecosystem. This article provides a can overview of that visit, beginning with the HQ tour, but mainly it is about putting several big questions users have about the brand’s change in support of Seagate, WD, etc on their 2025 devices.

Four core questions — based on direct community feedback — were put forward, addressing the motivation, risks, and future implications of Synology’s current drive support policy. Each answer is presented exactly as delivered. Note, this article is not sponsored by Synology and they have no control over the editorial stance and output! For users, partners, and industry observers alike, understanding these policy shifts is essential for making informed decisions about Synology systems moving forward.

Touring the Synology Headquarters

The Synology headquarters tour took place during a coordinated visit arranged alongside the Computex 2025 trade event. Approximately 30 to 40 individuals were in attendance, a mix that included official Synology partners, resellers, independent media, and technology commentators. The tour began with a structured company overview presentation outlining Synology’s operational history, business units, and market positioning.

While much of this information was familiar to long-term observers, it served to reinforce the company providing integrated storage and data management solutions. The presentation also included a brief overview of Synology’s global distribution and the evolving structure of its enterprise product lines.

Attendees were then guided through various areas of the facility, which covered several floors within a shared building. Synology does not occupy the entire structure, but the portions shown during the tour were substantial, comprising office sections, collaborative workspaces, logistics coordination areas, and support-related operations. Notably, many desks were temporarily unoccupied due to staff presence at Computex’s Nangang Exhibition Center.

Nonetheless, the offices remained populated with active terminals and systems undergoing live testing.

A significant portion of the tour focused on the environmental and durability testing facilities, including designated zones for acoustic profiling, thermal analysis, and dust resilience. The diversity of units being tested suggested coverage across multiple device classes, including both rackmount and desktop models.

The most extensive portion of the tour was the dedicated test and burn-in area. This floor was almost entirely devoted to long-term performance and diagnostic evaluations. Numerous Synology NAS units — some dating back to the early 2010s — were in continuous operation, either running synthetic workloads or undergoing compatibility assessments with the current DSM operating system.

The presence of so many legacy devices in active testing underscored the company’s emphasis on software longevity and cross-generational hardware support. However, it also provided a contrast to Synology’s new strict verification policies, especially given the mixed hardware environments visible during testing. The tour was led by ZP Kao, Sales Director at Synology, and Chad Chiang, Regional Manager for the UK and Germany, who offered clarification and responded to several direct inquiries during the walkthrough.

Why Has Synology Changed Its HDD Support Policy? Questions and Answers

Questions I put to Synology about their change in policy regarding verifying and supporting drive media being used on their 2025 and later series of NAS devices. I based these on the comments and suggestions from videos on the YouTube channel and comments on previous articles. I am under no illusions that these changes by Synology in their drive support policies have financial justifications (ranging from Support efficiency and it’s financial overhead, to the simple profitability of prioritizing their own labelled firmware optimized storage media choices over those of other brands), but I wanted to know if these were the only reasons for this? What other reasons could Synology provide to support this large and unpopular move. Thank you once again to Chad Chiang for taking the time to answer these questions.

Note – for a better understanding of the current DSM Support of Unverified media, as well as test scenarios detailing each setup and how DSM handles it, you can read it HERE in my Test Article.

How has the verification process changed for which drives you can use on Synology systems moving forward? And are there drive options from WD and Seagate currently undergoing support verification?

Answer – At Synology, we constantly reflect on a core question: Why do people choose a NAS? We believe the answer lies in the need for secure, reliable, and hassle-free data storage. This belief has guided our mission for over a decade. When analyzing our support history, the data clearly shows that systems using Synology-branded drives experience 40% fewer issues compared to those with third-party HDDs. This insight underscores the importance of using thoroughly tested drives. As for which third-party vendors are currently undergoing drive verification, we’re unable to disclose details. For the most accurate and up-to-date information, we recommend reaching out directly to the respective manufacturers.

The response positions Synology’s verification changes as a reliability-focused initiative and smooth platform running as the chief reasoning for them, referencing internal data that suggests a 40% reduction in support issues when Synology-branded drives are used. However, as mentioned previously, the statement does not provide supporting metrics such as sample size, timeframes, or specific failure modes, making it difficult to assess the scope or significance of this claim. I do not doubt that it is true, but without the X/Y and details of how this result was achieved, we are only getting half the story here.  The policy shift is framed as a precautionary measure aimed at minimizing user disruption, but the absence of transparency regarding ongoing verifications with WD or Seagate limits clarity for users seeking alternatives – which is why users are seeing this more as a means for the brand to increase profitability in the 2025 series as a bundled utility purchase – not as a means of system stability.

Ultimately, discussing the technical standards or benchmarks involved in the verification process in paramount here. It largely confirms that responsibility for future third-party compatibility lies with the drive manufacturers themselves, effectively shifting the onus of transparency to them. While it is understandable that Synology might want to mitigate support complexity, the lack of specificity about how the verification criteria have evolved or what steps vendors must follow leaves key questions unanswered for both users and third-party storage providers. I reached out to representatives from Seagate and WD to see if they could elaborate further on this new media side verification process with their respective NAS/Server class media – neither was able to provide further details at this time.

UPDATED 07-05-25 = Added Unverified HDD and SSD (Migrated) Storage Pool RAID Repair, RAID POOL Expansion and Hot Spare Tests. Right now, the following is what works and what does not (between pre-2025 Series and the 2025 Series that is releasing now):

Feature / Function	Pre-2025 Synology NAS<br>(e.g., DS1821+, DS920+, DS923+)	2025 Synology NAS<br>(e.g., DS1825+, DS925+, DS1525+)
DSM Installation – Verified Drives	Full support	Full support
DSM Installation – Non-Verified Drives	Allowed (with warnings)	Blocked completely
Drive Migration (Non-Verified Drives)	Fully functional, minor alerts	Works, but shows persistent warnings
Storage Pool Creation – Verified Drives	Fully supported	Fully supported
Storage Pool Creation – Non-Verified Drives	Allowed (with warnings)	Blocked
Storage Pool Expansion – Verified Drives	Fully supported	Fully supported
Storage Pool Expansion – Non-Verified Drives	Allowed (mixed arrays supported)	Blocked – drives flagged as incompatible
Hot Spare Assignment – Verified Drives	Fully supported	Fully supported
Hot Spare Assignment – Non-Verified Drives	Allowed	Blocked
RAID Recovery – Verified Drives	Supported	Supported
RAID Recovery – Non-Verified Drives	Supported	Blocked – system will not rebuild with unverified media
M.2 NVMe Cache – Synology SSDs	Supported	Supported
M.2 NVMe Cache – 3rd Party SSDs	Supported	Blocked
M.2 NVMe Storage Pools – Synology SSDs	Not supported	Supported
M.2 NVMe Storage Pools – 3rd Party SSDs	Not supported	Blocked
SMART Monitoring – Verified Drives	Full support	Full support
SMART Monitoring – Non-Verified Drives	Full support	Limited or blocked (TBC)
Storage Manager Alerts – Non-Verified Drives	Warnings, dismissible	Persistent, cannot be cleared
Overall Compatibility Flexibility	High – mix-and-match drives allowed	Low – walled-garden enforcement

Users are able to migrate existing storage arrays that feature Unverified/unsupported drive media in previous Synology systems into 2025 Plus series devices and still use DSM services – however once they do so, they are unable to use the same model ID of drives to perform RAID recovery, RAID expansion or introduced a hot spare, unless that drive is on the verified drive list. Why is this?

Answer- Advanced operations such as RAID recovery, expansion, or hot spare assignment are technically intensive and carry a higher risk of data loss if inconsistencies arise. Drives that haven’t been validated through Synology’s verification process may behave unpredictably under stress, impacting array stability or performance. For this reason, support for these functions is limited to verified drives—a precaution designed to safeguard user data and maintain long-term system reliability.

So, this answer outlines Synology’s rationale for restricting critical RAID operations on unverified drives and It emphasizes the increased risk associated with advanced storage operations, particularly when performed on drives that may not have been tested under stress or fault conditions. The justification focuses on data integrity and system reliability, suggesting that verified drives have undergone stress testing scenarios that others have not. However, the lack of granularity in what defines “unpredictable behavior” makes it difficult to independently evaluate the severity or frequency of these issues. Much like the statistics point earlier, this seems a remarkable stretch in terms of reaction to what many users would consider a very, very low % risk factor. Equally, though there is an argument that some drive media is less suitable for NAS usage (eg the WD Red SMR drives, desktop single drive use media like Seagate Barracuda and high power draw HDDs/SSDs in some cases), these make up a very small % of drive media in the market and using this as a reasoning to effectively bar the continued support of drive media that has been supported/used in Synology server use over the last 2 decades to prevent RAID recovery and Expansion in the latest gen for those carrying them over seems insane overkill.

The policy effectively limits upgradability and flexibility in mixed-drive environments. While it is technically reasonable to restrict risky operations on unvalidated components, the ability to migrate but not expand or rebuild a RAID introduces a half-measure — allowing users to enter unsupported configurations while restricting them mid-cycle. The result is a system state that may appear functional at first but ultimately lacks key functionality unless users conform to the verified list. For long-term users upgrading from older systems, this shift can lead to unexpected limitations without adequate warning, particularly in small or home office deployments. The messaging has been poor and though I made a video about these limitations (embedded above), there is practically no other clear and transparent information about this online (with incongruous detailson the Synology Knowledge base that could stand to be a lot clearer and louder).

HOT TAKE, and hear me out – If Synology do not allow support of RAID repair/Expansion on drives that have been migrated over from older NAS systems where the drives WERE originally supported (unless they use 2025 verified drives) because of reasons of stability, I have a somewhat extreme suggestion. As unpopular as it might have been, Synology should have just BARRED the support of migration from older generation Synology NAS devices with unverified drives entirely. I personally think they should have allowed for RAID repair/Expansion of unverified drives, but if they are going to pursue this for reasons of system stability, they should have committed to this fully and not allowed this grey area with migration. As it just looks bad for the brand, as means of ensuring people can upgrade/remain in the ecosystem, but then have limited scalability when those older drives require replacement/growth.

Were pre-populated Synology NAS devices considered, given the strict verified support stance that this new Synology hardware generation contains?

Answer – Regarding pre-populated NAS solutions, there hasn’t been significant internal discussion or a formal strategy around this model. As such, I don’t have a concrete answer at this time. The focus remains on ensuring that any storage media used—whether user-installed or bundled—is fully verified to meet Synology’s reliability standards.

Not much to unpack here. It makes sense. I imagine they DID discuss this as an option (as they are already engaging with this with systems like the Beestation), but at least for now, it seems off the table. As unpopular as this might have been, in some ways it could have solved a lot of this friction for some users. Provide the 2025 PLUS series as an empty/enclosure-only solution with similar compatibility as the 2024 and earlier generation – but then also supply several pre-populated options that feature Synology drive media as standard. However, that would be a different discussion entirely (eg logistics, SKUs, viability, ROI by offering this alongside flexible options).

Can you provide example(s) of critical system issues that using unverified drives caused, that were the tipping point for this new strict HDD support policy?

Examples of what stepped up our verification process moving forward:

Performance Issues: Unverified drives may function under light workloads but can suffer serious performance drops (e.g., IOPS decline) under multi-user access or when running demanding services like virtualization, backup, or databases. This can lead to poor user experience or service disruptions (e.g., iSCSI timeouts).

Stability Risks: Without thorough testing, unverified drives are more prone to failures under stress conditions such as unexpected power loss or long-duration file transfers—leading to timeouts, reboot failures, or data integrity issues in high-load or long-term operations.

Compatibility Problems: Drives not validated for compatibility may show unstable behavior with certain NAS controllers, resulting in drive drops, RAID instability, or data access interruptions over time.

Advanced Feature Failures: Unverified drives may fail during operations like SMART testing or Secure Erase, especially after unexpected power outages. Some drives may not respond properly under frequent access or specific command sets, affecting system stability.

Drive Failures Under High Load or Density: Some drives may become unresponsive under high data density or I/O intensity, with issues persisting even after a reset.

The examples provided by Synology highlight a variety of operational issues associated with unverified drives, most of which relate to performance degradation, system instability, or failure of advanced features under stress. These scenarios focus on workloads involving sustained I/O, power fluctuations, and controller-level interactions. In isolation, many of the issues described are plausible for lower-tier or unsuitable drive models, particularly in demanding or enterprise-like environments. That said, that are very low margins (eg 0.01% or lower) when you look at the traditional deployment of many Synology NAS solution in the Plus series. Again though, the scale and frequency of these issues remain unclear. There is no indication of how widespread such failures are across Synology’s user base, nor whether they represent rare edge cases or common occurrences. The examples also apply more logically to enterprise or high-density configurations, whereas the same strict policies now affect all tiers — including two-bay and four-bay systems used by home and prosumer users. Without concrete statistics or clearer thresholds, it is difficult to assess whether these issues justify the breadth of the policy. The policy appears to target potential worst-case scenarios, but may have broader consequences for user flexibility than the risk profile necessarily warrants.

Additional Information and Details from the MyBroadband Article

Further context on Synology’s new drive compatibility policy was provided in an interview between MyBroadband journalist Daniel Puchert (click to read) and Michael Chang, Synology’s Regional Sales Manager. The discussion reinforced many of the points raised during the HQ visit, while also offering additional information into the motivations behind Synology’s stricter approach to drive support in their latest generation of NAS systems. Chang explained that Synology’s primary objective was to ensure product reliability and reduce system-level faults that were increasingly traced back to third-party hard drives. According to Chang, complaints received by Synology often involved third-party drive issues, yet Synology would still be held accountable by users due to their role as the NAS provider. This prompted the company to centralize responsibility and tighten control over supported hardware configurations. While Synology-branded drives are currently the only models certified, Chang noted that other vendors are being invited to participate in the compatibility validation program — provided they meet the same testing standards.

(In the case of the NAS drives) “..because Synology’s product would typically facilitate the usage of third-party hard drives, it would also be the scapegoat for any faults with the entire system.”

“..complaints received by Synology regarding issues relating to its NAS devices were most often caused by faulty hard drives.

“severe storage anomalies have decreased by up to 88%” for hard drive models that have adopted its hard drive compatibility policy, compared to older models.”

“We still welcome third parties to join Synology’s ecosystem and have invited vendors to join our validation program,”

Michael Chang, Synology Regional Sales Manager – full article HERE

The article also mentioned that Synology-certified drives undergo over 7,000 hours of testing, and systems using those drives reportedly experience 40% fewer failures than those using uncertified media. Additionally, Synology claims that severe storage anomalies have dropped by up to 88% in systems following its compatibility policy. Although Chang confirmed that third-party compatibility may expand in the future, it will only do so under strict adherence to Synology’s internal benchmarks. These statements align with Synology’s position during the HQ tour, further emphasizing a shift toward a closed, highly controlled ecosystem that prioritizes consistent performance over hardware flexibility.

Synology and HDD Support and Verification – Conclusion and the Long Term

My biggest issue with all this is that, almost certainly, we are going to see Seagate, WD, Toshiba and more slow (slooooooooowly) appear on the compatibility lists for a number of the 2025 generation of devices over the coming months. So, what was all this for? The PR damage and likely early sales damage of the Synolgoy 2025 Series because of this change of support I would estimate is going to be pretty substantial – and all the reports and reactions to this online are not going to go away as soon as a Seagate Ironwolf or WD Red drive appears on the support lists. Also, Synology work on these devices for a very, very long time before launch – why is all this happening now – and not before launch. The cynic in me wants to just assume it was pure profitability and that Synology want to maximize profits, and if when this does begin to U-Trun ,that the brand can say that it was the plan all along. But whether that is true or not, the damage to the brand in the eyes of a substantial % of their long term fans is notable, and with many more players in the market (UniFi, QNAP, UGREEN and more) launching new products in Q3 and Q4 – is this all going to be a gamble by the brand that ends up costing them more than just leaving the support status quo where it was? Only time will tell.

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