Storage has a way of becoming the bottleneck nobody planned for. You upgrade the camera. You upgrade the rig. Then you sit there watching a progress bar crawl while four media cards offload one at a time. OWC wants to make that wait a lot shorter.
The OWC Express 4M2 Ultra is the first certified Thunderbolt 5 four-slot NVMe M.2 enclosure to hit the market. In plain terms, that’s a compact aluminum box that holds four SSDs of your choosing, runs them in RAID and hits real-world speeds up to 6,622MB/s. Let’s talk about what this actually buys you.
Real-world speed, in the edit bay and on the timeline
Storage marketing loves throughput figures that only matter on paper. This one shows up in the bay and on the timeline.
At 6,622MB/s, the Express 4M2 Ultra keeps pace with 12K RAW and 8K multicam without making you proxy everything first. OWC clocks multicam ingest at more than twice the speed of a typical 40Gb/s drive. For a DIT clearing cards between setups, that gap is the difference between staying ahead of the shoot and becoming the holdup.
That bandwidth comes from Thunderbolt 5 and its 80Gb/s pipe, routed through Intel’s Barlow Ridge controller. The full 6,622MB/s lands on an M3, M4 or M5 Mac. Older Thunderbolt 4 and USB4 machines still reach up to 3,200MB/s. Intel Macs on Thunderbolt 3 sit around 2,800MB/s. The enclosure scales to whatever bus it meets, rather than requiring the latest hardware to run at all.
A couple of details shape how close you get to that headline number, and both work in your favor once you know them. The 6,622MB/s figure comes from striping all four bays in RAID 0, the mode built for raw speed. Run a single drive or JBOD and you’ll see closer to 1,600MB/s, still plenty for most edits. Drive choice matters too. PCIe 4.0 and 5.0 SSDs unlock full speed, while the PCIe 3.0 sticks you might already own top out at around 3,800MB/s in RAID 0.
Your drives, your RAID, your call
Here’s where the Express 4M2 Ultra separates itself from a sealed off-the-shelf RAID. You build it.
Buyers who already own NVMe M.2 2280 or 2242 sticks can grab the empty enclosure and skip the retail markup on bundled drives. Drives pulled from old builds work fine here, too. Anyone starting fresh can buy the unit pre-populated instead. Either way, the box supports up to 32TB today across four 8TB drives. When 16TB sticks arrive down the road, they drop into the same enclosure with no need for replacement. That’s the part that earns the “future-ready” label. Most sealed RAID boxes lock you into the capacity you bought on day one.
RAID setup depends on which version you bought. OWC ships the Express 4M2 Ultra two ways. One comes bundled with its SoftRAID software. The other is a bare enclosure for buyers who’d rather supply their own. On the SoftRAID model, the menu covers RAID 0, 1, 4, 5, 10 or JBOD. That’s enough range for the speed chaser running a stripe and the DIT who wants RAID 5 redundancy on a working volume. SoftRAID also includes predictive health monitoring that flags a failing disk before it takes a project down. Cross-platform sharing lets an APFS or HFS+ volume be read on both Mac and Windows.
Pick the bare enclosure and the setup is yours to run. You configure the array in whatever RAID utility you already trust, and the box won’t push any software on you.
All four bays support hot plug. On macOS, each is bootable individually, which is a nice touch if you keep separate system drives for different clients or OS versions.
Scaling past a single box
Most enclosures hit a ceiling and leave you juggling drive letters across half a dozen drives. This one keeps going.
A second Thunderbolt 5 port on the back turns one Express 4M2 Ultra into the first link in a chain. Up to five more Thunderbolt devices can run off it, whether that’s a display, a ThunderBay 8 or another Express 4M2 Ultra. Four enclosures combine into 128TB presented as a single unified volume, with no performance hit as capacity grows. A solo shooter, future-proofing a setup and a production house building shared storage get the same path forward, which is rare at this price.
Compact, quiet and built to stay cool
Plenty of fast RAID boxes sound like a hair dryer the second they get busy. OWC took a different approach here.
The Express 4M2 Ultra stands 4.84 inches tall and weighs under two pounds. It’s smaller than a hardcover book and disappears next to a Mac Studio or mini. The aircraft-grade aluminum body pulls double duty as a passive heatsink, and a smart adaptive fan only spins up when drive temps actually climb. Light edits stay silent. Long sustained transfers ramp the fan to keep the drives from thermal throttling, which is the quiet killer of sustained write speed in cheaper enclosures. For anyone editing in a small room or recording scratch audio nearby, that restraint matters more than a spec sheet lets on.
Who it’s for and what it costs
This drive is built for people pushing serious data.
DITs and filmmakers offloading multiple cameras on set will appreciate the ingest speed and the thermal headroom for back-to-back transfers. Run the array as RAID 5 and a single drive failing mid-offload won’t take the day’s footage with it. Editors, colorists and VFX artists cutting 12K RAW or 8K ProRes timelines get a scratch volume that keeps pace with the heaviest playback. Power users who want full control over capacity and configuration finally get a Thunderbolt 5 platform that doesn’t make those decisions for them.
Compatibility is broad. The enclosure works with Thunderbolt 5, Thunderbolt 4 and USB4 on both Mac and PC, plus Thunderbolt 3 on Macs. Apple Silicon needs macOS 14.6 or later. Intel Macs want macOS 15 or newer. On Windows, you’ll need 11 24H2 or later.
The bottom line
The Express 4M2 Ultra makes a simple bet. Give creative pros the fastest Thunderbolt 5 RAID that fits in a compact box, then hand them the keys instead of welding the drive bays shut. For video pros tired of watching storage hold up the actual work, that mix of raw speed, build-it-yourself flexibility and room to scale is a strong starting point.
What stands out is how little it asks of you to get there. The footprint stays small enough to live on a crowded desk. The thermal design keeps it quiet through a long ingest. The drive bays stay open for whatever NVMe sticks make sense for your budget and your workflow. Those are the details that decide whether a drive becomes part of a daily routine or ends up forgotten in a drawer.
The bare enclosure starts at $399. The SoftRAID-equipped version runs $549, and includes three years of SoftRAID Premium, so check the configuration before you check out.
You can learn more about the Express 4M2 Ultra at owc.com/solutions/express-4m2-ultra. For editors balancing speed, silence, and flexibility, it feels built around real production demands rather than benchmark charts alone.
