Express 4M2 – 4-Slot M.2 NVMe SSD Enclosure Mac / PC / Thunderbolt 3


Infinitely configurable. Infinitely reconfigurable.

You like to explore your own independent path, and digital storage is where you have fun, push hard and spark the imagination. You explore, you refine, and when ready, you share your vision with the world. The OWC Express 4M2 is the external drive built for the journey before you and the path yet to be explored.

Customize your Express 4M2 with up to four NVMe SSDs, RAID them however you wish and connect it all with Thunderbolt 3 — the fastest and most flexible interface around. The sheer performance of the Express 4M2 helps you meet deadlines faster, giving you more time to explore your creativity and push your projects further.

Pint-Sized Powerhouse

Small in stature. Big on capability. The OWC Express 4M2 is ready to serve with four easy-to-access M.2 NVMe SSD slots customizable for any workflow with vibration damping feet that allow for vertical or horizontal orientation. Install up to 16TB of capacity and experience up to 2800MB/s of mind-bending performance via Thunderbolt 3. The Express 4M2 is an amazingly small digital workhorse with world-renowned OWC quality and award-winning support built in.

Ingest and duplicate dailies at breakneck speeds, work with higher resolutions, smoothly scrub through demanding timelines, and plow through thousands of photos with ease. The OWC Express 4M2 is one seriously fast drive to have by your side to take your digital capabilities to a new level.

Built Smaller and Faster from Input by Pros Like You

The OWC Express 4M2 is designed with superior ease-of-use in mind. We worked with award-winning creatives and listened to the kudos they heaped onto the OWC ThunderBay mini, and we put all that shared knowledge to good use when we set out to build the next-gen Thunderbolt 3 multi-bay drive. The result is the 57% smaller and 2.5x faster OWC Express 4M2.

It’s smaller and easier to fit into your workflow, studio and on stage. It’s faster with four easy-access M.2 slots so you can swap, upgrade or expand your Express 4M2 to configure and reconfigure it to serve any project need.

Game-Changing NVMe SSD Performance

NVMe (Non-Volatile Memory Express) is a hyper-efficient communications interface protocol built from the ground up to properly take advantage of SSD technology and high-performance connection buses like PCIe. The result is exponentially faster and efficient SSD storage, and the OWC Express 4M2 has room for four NVMe SSDs.


Display connection flexibility is yours with a convenient DisplayPort located right on the rear of the OWC Express 4M2. There’s no need to worry about adapters or extra long cables. Just plug your display directly into the Express 4M2 and you’re all set.


Configure and reconfigure your storage however you need by combining multiple OWC Express 4M2 drives together on Mac and Windows. Utilize the amazing capabilities of SoftRAID to RAID across multiple Express 4M2 drives, or add multiple Express 4M2 drives to your storage pool using Windows Storage Spaces.

More Powerful With SoftRAID

Need more power and protection? Choose a solution that includes OWC’s powerful SoftRAID RAID software.

SoftRAID is the most powerful, intuitive software RAID utility on the market. Multiple RAID levels let you select the RAID level that fits you or your project’s needs best. If you need maximum volume capacity, optimum drive performance, data protection, or a combination of attributes, SoftRAID has you covered.

Packed with features like drive validation, verification and failure prediction—SoftRAID includes features you simply don’t get with hardware RAID. It’s like having a datacenter on your desktop! From home users looking to protect photos and documents to professionals needing to protect and quickly access projects, SoftRAID is the perfect solution. Learn more about the power of SoftRAID XT.


  • Four M.2 NVMe SSD bays
  • Up to 2800MB/s
  • Compact design
  • Thunderbolt Certified for Mac and Windows
  • Includes Thunderbolt 3 cable

Product Specs

Product Specifications


  • Mechanisms Supported
  • NVMe 2280 M.2 SSDs
  • Display Support
  • Up to one 4K display @ 60Hz,
  • or one 4K display @ 30Hz,
  • or two 4K displays @ 60Hz
  • Display Support by Port
  • Mini DisplayPort 1.2: Up to 4K @ 60Hz
  • Bootable
  • All four drive bays are bootable on macOS. SSDs with 512 byte sectors require macOS 10.13 or later.
  • Hot Plug Support
  • Yes
  • Chipset
  • (1) Thunderbolt 3 – Alpine Ridge DSL6540
  • Certifications
  • CE
  • FCC
  • Data Transfer Rate (Maximum)
  • Thunderbolt 3 : 40 Gb/s (or 5000 MB/s)


  • RAID Capable
  • Yes
  • RAID Features
  • Software RAID


  • MTBF (Mean Time Between Failures)
  • Varies depending on drive mechanism installed
  • Contact Start Stops
  • Varies depending on drive mechanism installed


  • Mac OS Compatibility
  • macOS 10.12 Sierra
  • macOS 10.13 High Sierra
  • macOS 10.14 Mojave
  • macOS 10.15 Catalina
  • macOS 11.0 Big Sur
  • macOS 11.1 Big Sur
  • PC OS Compatibility
  • Windows 10 32-bit Edition
  • Windows 10 64-bit Edition
  • Windows Server 2016
  • Other Requirements
  • When using one or more SSDs with 512 byte sectors, macOS 10.13 or later is required.
  • Host Port Requirements
  • Thunderbolt 3 or later
  • Driver Required
  • No


  • Power Supply
  • External UL-listed universal auto-switching power supply
  • AC Input
  • 100-240V, 50-60Hz, 1-2A
  • DC Output
  • +12V, 6A
  • Wattage
  • 72W Watts
  • External Power Adapter
  • Yes
  • Power Delivery
  • Two Thunderbolt 3 ports with 15W power delivery each.


  • Number of Bays
  • 4
  • Device Ports
  • (2) Thunderbolt 3 (USB-C) Ports
  • (1) DisplayPort Port
  • Cooling
  • (1) 60mm 2,800RPM None cooling fan
  • Security Slot
  • No
  • Power/Activity LED
  • Yes
Learn more