Meet the OWC Express 4M2 Ultra: Blazing Fast, Compact, DIY Thunderbolt 5 RAID That Scales

Order It Your Way

The 4M2 Ultra gives you the ability to order the drive you need. If you already have NVMe M.2 SSDs on hand, order the empty enclosure, install your own drives, and keep costs down. If you’re starting fresh, you can order a pre-populated 4M2 Ultra with drives already installed.

Either way, the flexibility doesn’t stop at purchase. The 4M2 Ultra supports up to four NVMe M.2 2280 or 2242 SSDs for a total capacity up to 32TB. And because it’s DIY-friendly, swapping in new and/or higher capacity drives as your storage needs grow is quick and easy. (But that's not the only way to expand capacity. More on that in a bit.)

Your RAID configuration is equally flexible: choose from RAID 0, 1, 4, 5, 10, or JBOD, managed through OWC SoftRAID (included with select models).

Crazy Speed

Express 4M2 Ultra takes advantage of every bit of the 80Gb/s bandwidth Thunderbolt 5 has to offer. Whether you’re editing 12K RAW footage, managing 8K multi-cam sequences, batch-processing high-resolution stills, or working with massive data sets, the 4M2 Ultra’s 6,622MB/s of real-world throughput means your workflow won’t slow down.

Daisy Chain for Massive, Unified Capacity

The 4M2 Ultra also includes a second Thunderbolt 5 port that you can use to connect up to five additional Thunderbolt devices like a display or another Thunderbolt drive like our ThunderBay 8.

But it also means you can connect more Express 4M2 Ultra enclosures and combine them into a single, unified high-capacity volume—all without a hit to performance.

Small Footprint. Smart Thermal Management.

At 2.36 in. wide × 4.84 in. tall × 4.60 in. deep and under 2 pounds, the Express 4M2 Ultra puts extraordinary performance in a remarkably compact package. The solid aircraft-grade aluminum body handles passive heat dissipation, while a smart adaptive fan adjusts speed based on drive temperature.

This intelligent cooling system keeps the drive quiet during lighter workloads but can ramp up the fan under heavy, prolonged transfers to preserve peak sustained performance.

All four drive bays support hot plug, and each bay is individually bootable on macOS.

Broad Compatibility Across Mac and PC

The Express 4M2 Ultra works with:

• Thunderbolt 5, 4, and USB4 — Mac and PC

• Thunderbolt 3 — Mac only

• Apple silicon Macs: macOS 14.6 or later

• Intel Macs: macOS 15.x or later

• Windows 11 24H2 or later

Key Specifications at a Glance

• Interface: Thunderbolt 5 (80Gb/s), Thunderbolt 4, Thunderbolt 3 (Mac), USB4

• Drive Bays: 4 × NVMe M.2 2280 or 2242 (single- or double-sided, M Key)

• Max Speed: Up to 6,622MB/s

• Max Capacity: Up to 32TB

• RAID Support: RAID 0/1/4/5/10/JBOD (software RAID)

• Ports: 2 × Thunderbolt 5 (USB-C) — uplink + downlink

• Chipset: Barlow Ridge JHL9480

• Cooling: Smart adaptive fan + aircraft-grade aluminum housing

• Dimensions: 2.36 in. (W) × 4.84 in. (H) × 4.60 in. (D)

• Weight: 1.9 lbs (0.9 kg)

• Warranty: 3-Year OWC Limited Warranty

Pricing and Availability

The OWC Express 4M2 Ultra is available for pre-order now:

• Starting at $399.99 (without SoftRAID)

• Starting at $549.99 (with SoftRAID)

Shipping begins Q3 2026. Pre-order the OWC Express 4M2 Ultra right here on OWC.com.