If you’ve been eyeing a high-capacity or RAID storage solution for your Mac but found the options either too bulky, too slow, or too limiting, we’ve got something pretty exciting to share that will give lots of you the desktop storage solution you’ve been waiting for.
This is the new OWC Express 4M2 Ultra, the world’s first certified Thunderbolt 5 four-slot NVMe M.2 SSD enclosure. Express 4M2 Ultra is designed to make serious, fast, expandable and RAID-able storage feel approachable and attainable for Mac users of all types.
Apple’s latest Macs ship with Thunderbolt 5, and that port is capable of far more than most high-capacity RAID drives have been able to take advantage of—until now. The Express 4M2 Ultra delivers eye-watering real-world speeds, huge capacities that can also be expanded through the magic of Thunderbolt, full RAID support, and all in a package barely larger than a hardcover book.
Oh, and did we mention it’s DIY friendly?
Maximum Flexibility
The 4M2 Ultra is available as an empty enclosure or pre-populated with drives, depending on what you need. Already have some NVMe M.2 SSDs you can pop in? Order the enclosure on its own, drop your drives in, and save some cash. Starting from scratch? Order a pre-configured 4M2 Ultra with drives already installed and ready to go—all with the knowledge that if you need more capacity down the road, swapping or adding drives is extremely easy. (But that’s not the only way you can expand your storage capacity with Express 4M2 Ultra! More on that in a bit.)
Either way, the enclosure supports up to four M.2 2280 or 2242 NVMe SSDs for up to 32TB total capacity. The drive supports RAID 0, 1, 4, 5, 10, or JBOD, managed through OWC SoftRAID (included with select models).
With Thunderbolt 5’s 80Gb/s bandwidth behind it, your RAID can now hit real-world speeds up to 6,622MB/s. That’s fast enough to handle 12K RAW video, 8K multi-cam sequences, and batch processing of high-resolution images without breaking a sweat.
What’s New Compared to the Standard Express 4M2: Speed and Daisy Chaining
The standard Express 4M2 is a capable, compact NVMe enclosure built on USB4 technology. That makes it highly compatible with Thunderbolt 5/4/3 and USB 3 host systems while also allowing it to reach tops speeds of around 3200MB/s. But because 4M2 Ultra is built on Thunderbolt 5, it takes the capability of this drive up several notches.
Thunderbolt 5 unlocks a substantial leap in bandwidth, and we built the enclosure from the ground up to take full advantage. Not only does Express 4M2 Ultra offer double the transfer speeds of the standard Express 4M2, it also includes a second Thunderbolt 5 port. With this second port, you can daisy chain up to five additional Thunderbolt devices.
Of course, that means you could connect your 4M2 Ultra and then daisy chain a display or other peripheral. But, more importantly, it also means that you can daisy chain another or multiple 4M2 Ultras together and combine them into a single massive volume without sacrificing performance. So cool.
Plus, because this is Thunderbolt 5, you’ll still have a drive with broad compatibility: Thunderbolt 5, 4, and USB4 systems on both Mac and PC are supported, and Thunderbolt 3 support is available on Mac.
Built to Fit Any Desk Setup
Express 4M2 Ultra’s aircraft-grade aluminum housing isn’t just for aesthetic purposes. It delivers extremely effective thermal management that works in tandem with a smart adaptive fan, intelligently adjusting fan speed based on drive temperature. This keeps things quiet during everyday tasks while also being able to ramp up the cooling when you’re pushing through a heavy 8K+ edit session to keep performance strong. All four drive bays support hot plug, and each bay is individually bootable on macOS.
At just 2.36 in. wide, 4.84 in. tall, and 4.60 in. deep and weighing under 2 pounds, the 4M2 Ultra takes up minimal real estate on your desk. That’s a huge amount of performance in a very small footprint.
See It Live at NAB 2026
The OWC Express 4M2 Ultra will make its public debut during NAB 2026 at OWC Booth #N2373 in the North Hall. If you’re attending the show, you’re definitely going to want to check this thing out.
The 4M2 Ultra is available for pre-order now, starting at $399.99 for non-SoftRAID models and $549.99 with SoftRAID included. Shipping is expected to begin in Q3 2026.
