New Thunderbolt 5 NVMe Storage Solution Revealed – The OWC 4M2 Ultra
New Thunderbolt 5 NVMe Storage Solution Revealed – The OWC 4M2 Ultra
OWC has introduced the Express 4M2 Ultra at NAB 2026 as a compact 4 bay NVMe enclosure built around Thunderbolt 5. It is designed as a DIY storage solution for users who want to install their own M.2 SSDs and configure the enclosure for different RAID modes, including RAID 0, 1, 4, 5, 10, and JBOD. OWC positions it as a high performance option for media production, post production, and other bandwidth intensive workloads that benefit from fast external solid state storage.
The enclosure supports up to 4 NVMe M.2 drives in 2280 or 2242 formats and is rated for up to 6622MB/s in RAID 0 when paired with PCIe 4.0 or newer SSDs on Thunderbolt 5 systems. It also retains backward compatibility with Thunderbolt 4, Thunderbolt 3 on Mac, and USB4 hosts, though throughput is lower on 40Gb/s connections. Capacity starts with whatever drives the user installs, with support for up to 32TB in a single unit based on current 8TB SSD support, while additional units can be daisy chained for larger storage pools.

| Specification | OWC Express 4M2 Ultra |
|---|---|
| Product type | External DIY NVMe RAID enclosure |
| Drive bays | 4 x M.2 SSD |
| Supported drive sizes | M.2 2280, M.2 2242 |
| Drive type | NVMe SSD, PCIe Gen 3 and later |
| Max stated speed | Up to 6622MB/s |
| Host interface | Thunderbolt 5 |
| Secondary compatibility | Thunderbolt 4, Thunderbolt 3 on Mac, USB4 |
| RAID modes | RAID 0, 1, 4, 5, 10, JBOD |
| Max stated capacity per unit | 32TB |
| Daisy chain expansion | Up to 128TB as stated with multiple units |
| Cooling | 40mm adaptive fan |
| Material | Aluminum |
| Price | Starts at $399.99 |
| Availability | Pre-order now, ships Q3 2026 |
OWC Express 4M2 Ultra – Design & Storage
The Express 4M2 Ultra uses a compact aluminum enclosure with a vertical desktop form factor intended to keep its footprint relatively small. OWC states that the chassis is built from aircraft grade aluminum, which serves both as the structural housing and as part of the thermal design. The unit measures 12.3 cm tall, 11.7 cm long, and 6.0 cm wide, with a listed weight of 900 g.
Internally, the enclosure provides 4 drive bays for NVMe M.2 SSDs and supports both 2280 and 2242 form factors. It accepts single sided and double sided drives, though SSDs with integrated heatsinks are not supported. OWC specifies support for PCIe Gen 3 and later SSDs, with Gen 4 and newer drives recommended for higher performance. Each bay operates at PCIe 4.0 x1, and single drive performance is rated at up to 1600MB/s.

From a storage flexibility standpoint, the enclosure is aimed at users who prefer to source and install their own drives rather than buy a preconfigured array. That allows the capacity and performance profile to vary depending on the SSDs installed. With current 8TB drives, the maximum listed capacity is 32TB in a single enclosure, while future higher capacity drives could increase that figure without requiring a new chassis.
RAID support is handled in software rather than through a dedicated hardware RAID controller. The Express 4M2 Ultra supports RAID 0, 1, 4, 5, 10, and JBOD, with OWC highlighting SoftRAID as its main management option. This gives users a wider range of configuration choices depending on whether they prioritize throughput, redundancy, usable capacity, or a balance between those factors.
Thermal management is handled by a 40mm cooling fan with multiple speed thresholds tied to internal temperature. According to OWC’s listed profile, the fan remains off below 35°C, then ramps progressively from 40% to 100% as temperatures rise from 35°C to 55°C and above. The stated approach is to reduce unnecessary noise under lighter workloads while maintaining SSD performance during sustained transfers.

OWC Express 4M2 Ultra – Ports and Connections
The Express 4M2 Ultra uses Thunderbolt 5 as its primary host interface, with 1 USB C host port rated for up to 80Gb/s. OWC also lists support for USB Attached SCSI Protocol, and the enclosure is designed to work across Thunderbolt 5, Thunderbolt 4, USB4, and Thunderbolt 3 on supported Mac systems. In practice, that gives it a broader compatibility range than a Thunderbolt 5 only accessory, though maximum throughput depends on the bandwidth available from the connected system.
A second Thunderbolt 5 port is included for downstream connectivity. OWC states that this allows users to daisy chain up to 5 additional Thunderbolt devices, along with 1 USB peripheral, from the same connection path. The same port can also be used to connect additional Express 4M2 Ultra units, with OWC positioning that as a way to build larger storage volumes without treating each enclosure as an entirely separate destination.
Compatibility varies by platform and interface generation. On newer Thunderbolt 5 Macs and PCs, OWC rates the enclosure at up to 6622MB/s, while Thunderbolt 4 and USB4 systems are listed at up to 3200MB/s. Intel Macs with Thunderbolt 3 are rated up to 2800MB/s, and OWC notes that Thunderbolt 3 support is Mac only. No driver is required, and the enclosure is listed as compatible with macOS 14.x Sonoma, macOS 15.x Sequoia, macOS 26.x Tahoe, Windows 11, and Linux, with some features depending on OS version and connection type.

OWC Express 4M2 Ultra – Price and Release date
OWC has set the starting price of the Express 4M2 Ultra at $399.99 for the standard non SoftRAID version. A version bundled with SoftRAID is priced at $549.99. As a result, the enclosure enters the market as a premium DIY storage option rather than a low cost external SSD enclosure, with the final overall build cost depending heavily on the NVMe drives a buyer installs.
The company says the Express 4M2 Ultra is available for pre order now following its reveal at NAB 2026 in Las Vegas. OWC lists shipping for Q3 2026, so early buyers will still be waiting several months for general availability. That places the launch window firmly in the second half of the year, even though orders have already opened.

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