Mac or PC featuring Thunderbolt or Thunderbolt 2 interface
(1) Thunderbolt 3 - Alpine Ridge DSL6540
(2) USB-C and Power Delivery - Texas Instruments TPS65983
(2) Thunderbolt 3
Max Transfer Rate
Thunderbolt 3: 40 Gb/s (5000 MB/s)
4K @ 60Hz
Bootable with systems that support booting from RAID volumes. Not bootable with macOS 10.14 Mojave or later.
(4) M.2 - 2280 "M Key" (PCIe 3.0 x1 per slot)
(4) M.2 NVMe or
(4) M.2 AHCl (PCle only)
Hardware or Software RAID
RAID Levels Supported
RAID 4 *Note 2
RAID 5 *Note 2
RAID 10 *Note 2
Kensington Security Slot
Yes (Power and Activity)
Plug and Play
Internal UL-listed universal auto-switching
AC input: 100 ~ 240V, 50/60Hz
DC output: 12V, 7.5A
Operating: 32°F to 104°F (0°C to 40°C)
Non-Operating: -4°F to 158°F (−20°C to 70°C)
Height: 6.0 cm (2.4 in)
Length: 11.3 cm (4.4 in)
Width: 13.6 cm (5.4 in)
800.0 g (1.76 lbs)
SSDs using 512b sector sizes require macOS 10.13 or later.
SoftRaid XT required for RAID 4,5, and 10
Host computers with a Thunderbolt or Thunderbolt 2 port require the Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter.
Does not support Dual-Mode DisplayPort (DP++). Adaptable to HDMI, DVI, and VGA via active adapters. Supports Multi-Stream Transport (MST), although MST is not currently supported by macOS.
Some Samsung drives may require a firmware update to work with the Express 4M2. Samsung 970 EVO drives must use version 2B2QEXE7 or later, while 970 EVO+ drives must use 2B2QEXM7 or later. More information is available at the following link regarding OWC Express 4M2 Drive Compatibility.