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8.0TB Accelsior 4M2
PCIe M.2 NVMe SSD Adapter Card

New Condition | Open Box

High-Performance PCIe M.2 NVMe SSD Adapter Card
Meet The Fastest SSD Available
When OWC launched its first Solid State Drive in 2010, it was engineered to deliver the same attribute formula that Mac and PC users expected from OWC external storage solutions:
High performance + high reliability + affordable price = The OWC Difference
Nearly a decade later, our commitment to that winning formula remains steadfast as we push the boundaries of leading-edge SSD development with the Accelsior 4M2. It’s ideal for uncompromised, data intensive, high bandwidth needs like large format video editing, VR/AR/MR environments, high transactional and complex calculation applications, and extreme gaming.
Accelsior 4M2 houses up to four high-performance Phison E12 M.2 NVMe SSDs under a finned heat sink cover that provides silent, throttle-free cooling. These “blade” style SSDs utilize Triple-Level Cell (TLC) 3D NAND with SLC caching and 7% over-provisioning.
All those “ingredients” combine to deliver over 6,000MB/s real-world speed with the highest reliability possible to satisfy the biggest storage performance appetite.
Highly Versatile with Mobile Possibilities
Whether you have the Mac Pro 2019, a Mac Pro 2012 or 2010, or PC tower, Accelsior 4M2 can go to work for you. As a half-length x8/x16 compatible card, this game-changer offers the versatility you need, so you’re not tied to one PCIe slot size or limited by a space-confined computer case.
You can also enjoy the performance boosting benefits of Accelsior 4M2 with your Thunderbolt 3-equipped notebook computer, iMac workstation, or slot filled gaming rig. It’s Plug and Play easy with a PCIe expansion chassis like the OWC Mercury Helios 3S (sold separately and coming soon).
Change Your Reality
Accelsior 4M2 offers performance gains in so many diverse ways that it will change the reality of how you use a storage solution:
  • Stream and edit high-res video and graphics files without a glitch.
  • Experience faster previews, renders, and processing in VFX programs.
  • Keep page scenery and textures looking sharp and flowing uninterrupted in virtual reality environments.
  • Ensure augmented reality visualizations look life-like.
  • Change game levels seamlessly and play flight/driving/MMO games with continuously changing scenery and heavily personal preference modded games without micro-stuttering.
  • Give your computer a significant speed boost with improved system “snappiness”, a fast OS boot drive, or a bottleneck-free scratch drive.
Includes SoftRAID: Easy and Complete Drive Management
Accelsior 4M2 includes SoftRAID software to help you manage your data like a pro. You can maximize drive space, get the fastest access speeds, and protect against drive failure with plug-and-play simplicity. SoftRAID’s easy setup makes it a breeze to create RAID volumes by helping you through the entire process. Just decide what you’re using your RAID volume for and how much space to allocate to it. It's that simple to create your preference of speed and/or redundancy attributes of your data volume. Learn more about SoftRAID.
Professional Grade = Ready to Work
We understand having confidence in gear reliability is paramount to creative professionals. That’s why every Accelsior 4M2 pre-configured solution undergoes a multi-step performance certification prior to shipping. This ensures your Accelsior 4M2 arrives operating properly and immediately ready for demanding use.

Product Specifications:

OWC Part Number

  • SSDACL4M208T

macOS Compatibility

  • macOS 10.13 High Sierra
  • macOS 10.14 Mojave
  • macOS 10.15 Catalina

Windows Compatibility

  • Windows 10 32-bit Edition
  • Windows 10 64-bit Edition
  • Windows Server 2016

Other OS Supported

  • Linux kernel versions 5.4 or later

Other Requirements

  • macOS requires 10.13.6 or later

RAID Support

  • Yes

RAID Management

  • Software RAID (SoftRAID)


  • 8.0 TB

Formatted Capacity

  • 7451 GiB

Card Type

  • Full Height Half Length PCIe

Activity Light

  • Yes

PCIe Type

  • PCIe 3.0

PCIe Lanes

  • x8

Controller Chipset

  • ASMedia ASM2824

NAND Flash Components

  • Toshiba Synchronous Triple-Level Cell (TLC) 3D NAND Flash

S.M.A.R.T. Attributes

  • Standard attributes supported

Native Command Queuing (NCQ)

  • Up to 32 simultaneous commands

External Connectivity

  • None

Internal Connectivity

  • (4) NVMe 1.3 M.2 Slots (PCIe 3.0 x4)

Internal Connector Form Factor

  • M.2 - 2280 "M Key"


  • Sequential Read (Max) Up to 6318 MB/s
  • Sequential Write (Max) Up to 6775 MB/s
  • Sequential Read (Average) 6280 MB/s
  • Sequential Write (Average) 6356 MB/s

Nonrecoverable Read Errors

  • 1 per 1016 bits read

TRIM Support

  • OS Dependent

Error Correction

  • Built-in ECC


  • 3115TB total bytes written (TBW), equal to 1220 GB per day for 7 years


  • CE
  • FCC


  • Yes


  • Environmental (Operating)
    • Temperature (°F) 41° — 107°
    • Temperature (°C) 5° — 42°
    • Humidity 8% to 90% non-condensing
    • Altitude -304.8 m to 3,048.0 m (-1,000 ft to 10,000 ft)
  • Environmental (Non-Operating)
    • Temperature (°F) −40° — 149°
    • Temperature (°C) −40° — 65°
    • Humidity 5% to 95% non-condensing
    • Altitude -304.8 m to 12,192.0 m (-1,000 ft to 40,000 ft)


  • Height: 12.6 cm (5.0 in)
  • Width: 2.2 cm (0.9 in)
  • Length: 18.1 cm (7.1 in)


  • 381.0 g (0.84 lbs)


  • Idle (Typical) 0.0 bels
  • Seek (Typical) 0.0 bels


  • Before installing this product in a host device, write down the SoftRAID serial number that is listed on the back of the PCIe card. It is needed to setup the SoftRAID application.
  • Data transfer rates will vary based on SSDs used, CPU speed, RAID setting, and PCIe version.
  • Backward compatible with PCIe 2.0 slots with reduced speeds.
  • Performance in a Thunderbolt 3 PCIe expansion chassis limited by maximum Thunderbolt 3 PCIe bandwidth of 2800MB/s.
  • Bootable using a single, independent M.2 startup disk, with the other three M.2 SSDs configured as independent volumes or as a software RAID (SoftRAID or Apple RAID). 10.14.6 required on 2010-2012 Mac Pro. 10.15.1 or later required on 2019 Mac Pro.
Manufacturer provided specifications for Other World Computing p/n SSDACL4M208T UPC#: 810586033190


Note:Please click here to review important Mac Pro install limitations and notes.
This product is compatible with... Learn how to find your Mac's model ID
Mac Pro
Mac Pro (Late 2019)
(December 2019)
Model ID: MacPro7,1
2.5GHz 28-Core
Install videos coming soon
Mac Pro
Mac Pro (Late 2019)
(December 2019)
Model ID: MacPro7,1
2.7GHz 24-Core
Install videos coming soon
Mac Pro
Mac Pro (Late 2019)
(December 2019)
Model ID: MacPro7,1
3.2GHz 16-Core
Install videos coming soon
Mac Pro
Mac Pro (Late 2019)
(December 2019)
Model ID: MacPro7,1
3.3GHz 12-Core
Install videos coming soon
Mac Pro
Mac Pro (Late 2019)
(December 2019)
Model ID: MacPro7,1
3.5GHz 8-Core
Install videos coming soon
Mac Pro
Mac Pro 4-Core (Mid 2010)
(July, 2010)
Model ID: MacPro5,1
2.8GHz, 3.2GHz
Mac Pro
Mac Pro 6-Core (Mid 2010)
(July, 2010)
Model ID: MacPro5,1
Mac Pro
Mac Pro 8-Core (Mid 2010)
(July, 2010)
Model ID: MacPro5,1
Mac Pro
Mac Pro 12-Core (Mid 2010)
(July, 2010)
Model ID: MacPro5,1
2.66GHz, 2.93GHz
Mac Pro
Mac Pro 4-Core (Mid 2012)
(June, 2012)
Model ID: MacPro5,1
Mac Pro
Mac Pro 6-Core (Mid 2012)
(June, 2012)
Model ID: MacPro5,1
Mac Pro
Mac Pro 12-Core (Mid 2012)
(June, 2012)
Model ID: MacPro5,1
2.4GHz, 2.66GHz, 3.06GHz
OWC Helios
OWC Mercury Helios 3S
Thunderbolt 3 PCIe
expansion chassis
3.5-inch Enclosures
AKiTiO Node Duo
Thunderbolt 3 PCIe Expansion Chassis
Model # AKT3N2AA0002Y
3.5-inch Enclosures
Akitio Node Lite


  • (1) Accelsior 4M2
  • (1) SoftRAID
  • (1) Quick start guide
8.0TB OWC Accelsior 4M2 PCIe Card Mfr P/N: SSDACL4M208T OWC SKU: OWCSSDACL4M28TO OWC’s fastest SSD ever with up to 6000MB/s speed for large format video editing, VR/AR/MR environments, extreme gaming, and other high bandwidth needs 5 Year OWC Limited Warranty Ships: Same Day
Supply Limited: 1 available
Only $1,999.75Garage Sale Price $1,678.75
Add to CartOther World Computing SSDACL4M208T In Stock, Click to Buy Now
Additional Capacities:
  • 2.0TB
    • Ships: Same Day
    • Only $679.99
    • Garage Sale Price $568.75
  • 8.0TB