OWC Accelsior S PCIe Adapter for 2.5" SATA III SSD Drives

OWC Accelsior S PCIe Adapter for 2.5" SATA III SSD Drives
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The Accelsior S Storage Expansion from OWC / Other World Computing allows you to add high speed SATA III drive to PCs or silver Mac Pro towers, otherwise restricted to SATA II architecture. With more than 500 MB/s of throughput, the Accelsior S dual-lane PCIe 2.0 card delivers flexible storage expansion, with a speed boost, to your Mac or PC. Accelsior S is the complement to OWC's Mercury family of SSD's, allowing up to an extra 1TB of fast storage expansion.

Mount a 2.5" drive to the Accelsior S, install in any available PCIe x4 (or greater) slot, and you're up and running with expanded storage. Use as a native boot drive or scratch-disk and boost capacity and performance. With no drivers or extra software needed, upgrading your PC or legacy Mac Pro tower with Accelsior S is easy.

Directly mount any standard 2.5" drive
Up to 550 MB/s sustained speeds
Enhance SATA II (3 Gb/s) systems with SATA III (6 Gb/s) support
No drivers required
Easy installation
UPC: 812437021035


Designed For Use WithAll 2.5" HDD and SSD SATA I (1.5 Gb/s), SATA II (3 Gb/s), and SATA III (6 Gb/s)
InterfacePCIe 2.0 x2
ControllerHBA: Asmedia 1062
Form FactorFull height, half length
ReadUp to 550 MB/s (depends on mechanism installed)
Write530 MB/s (depends on mechanism installed)
ComplianceRoHS, AHCI
Acoustics0.0 bels for both Idle and Seek
Operating Systems SupportedMac OS X 10.6 and up
Windows Server 2008 and higher
Not compatible as a Windows boot drive on a Mac
Operating Temperature32 to 158°F (0 to 70°C)
Non-Operating Temperature-67 to 302°F (-55 to 150°C)
Packaging Info
Package Weight0.355 lb
Box Dimensions (LxWxH)8.65 x 6.35 x 1.8"


Add an SSD to Mac Pro

By Dalton
Rated 5 out of 5
Date: 2020-09-01

I added a Samsung QVO 870 1TB SSD to my mid 2010 Mac Pro using this PCIe card. I'm getting 530/MBs read and 500MBs write. I'm totally satisfied with that considering that this card is said to give 550/MBs of throughput, and Samsung advertises the QVO 870 as 560/MBs on the read and 530 on the write.

Very easy

By Robert
Rated 5 out of 5
Date: 2018-06-26

As with most OWC products, I'm very satisfied. Install SSD drive of your choice and enjoy the increased transfer/read speed. I use it for my boot drive with a 5.1 Mac Pro.

Writing Speed is low.

By Kunduz
Rated 3 out of 5
Date: 2018-04-24

I have a Mac Pro 5.1 and use this card with Mercury Extreme Solid Drive. Reading speed is over 500 MB but writing speed is like 230 MB. Other than that it is fast. No problem so far.

Will not boot in all PCs

By ken
Rated 2 out of 5
Date: 2018-03-31

I bought this so I could use a Samsung SSD to boot my PC computer (Dell T5500).� But after hours of research and contacting tech support, it is clear that it cannot be used for a boot drive in my computer.� The BIOS will not recognize the device, and I am using the latest bios available for my computer.� The adapter works fine if you do not want to boot from it, however.� So beware, the description for this product is misleading.� If you want a boot device, get the IOCrest PCI Express card instead, but definitely do not use their drivers!� Use the default Windows drivers instead.

Functions differently than other PCIe Adapters

By Brendan
Rated 3 out of 5
Date: 2019-04-17

Works great, but I have found it kind of annoying that this shows up as an External (and unmountable/ejectable) whereas the Apricorn PCIe adapters I have do not. It can be remounted via disk utility but its been a problem already when I have other editors using the machine who dont know the quirks this deal has


By Marconi
Rated 5 out of 5
Date: 2019-02-13

It took my Mac pro 2012 to the next level. Highly recommended.

This is the one..

By Steve
Rated 5 out of 5
Date: 2018-11-28

If your like me and were looking for a faster PCIe replacement for the discontinued Apricorn Velocity X2 ( the X1 card is nowhere as fast ), then this is the card youll want to order.  While the OWC only gives you the single 2.5 inch connection, the Apricorn X1 does give you an extra SATA input ( which is nice ) but with the Apricorn X2 speed no longer available this is your best option.

Mac OS Update Failure

By Barry
Rated 2 out of 5
Date: 2018-09-20

We purchased 14 of these for our v4,1 and v5,1 Mac Pro's which had already been updated with Micron 500GB SSD's. The v4,1 Mac Pro's also had the Flash ROM Update convert them to v5,1 units. Unfortunately, all attempts to upgrade the Mac OS from 10.11.6 (El Capitan) to 10.13.6 (High Sierra) failed. After download the computer would not shutdown to initiate the install. We were forced to remove the OWC PCIe adapter, reinstall the SSD drives back on their NewerTech SATA Adapters before the OS update would complete successfully. After the OS update the SSD drives were reinstalled o the OWC PCIe adapters and would boot and run without and problems.

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Will this work with a new Mac Pro tower and this ...

Will this work with a new Mac Pro tower and this SSD? https://www.bhphotovideo.com/c/product/1606521-REG/samsung_mz_77e2t0b_am_2tb_870_evo_sata.html
Asked by: Chris
Yes, the Samsung SSD will work with that setup.
Answered by: OWC Andy
Date published: 2021-03-09

Will this work with a 2019 Mac Pro ?

Will this work with a 2019 Mac Pro ?
Asked by: Todd
Yes, it will work.
Answered by: OWC Andy
Date published: 2020-03-11


Will it work in MacPro 3,1 (early 2008)?
Asked by: Dmitry L.
yes. For full bandwidth, install card in one of the x16 PCIe 2.0 slots.
Answered by: Peter S.
Date published: 2018-08-26


Hi. The BIOS in my PC will recognize a 4TB SSD as 2TB only and pass this size to Windows 10 64-bit, which will also report 2TB size. However, when I connect 4TB SSD to my PC via a USB enclosure, Windows 10 will see the full 4TB size. Will this card work similarly with a 4TB SSD and allow Windows 10 64-bit to recognize the full 4TB size? Thank you.
Asked by: Anonymous
An up to date computer running a 64 bit OS should be able to see large drives with no issue. Did you format the drive as Fat32?
Answered by: Andy L. NewerTech Expert
Date published: 2018-10-24
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