I created a mirrored RAID (RAID 1) using 2 Western Digital 2TB external hard drives before, using Disk Utility on a Mac. For this, it should be software RAID.

And then I got a WD Thunderbolt Duo 6TB, with two 3TB drives in it.

The question is, it seems that I can just create a RAID set inside of Disk Utility, as RAID 1, and then I will have a 3TB mirrored drive. It doesn't say it is software RAID or hardware RAID, and I assumed it is software RAID. Let's call this Process 1.

But when I go to Western Digital's website and downloaded the drive's utility and use it to erase the drive and configure it as RAID 1, close the app, and then use Disk Utility to view the drive, it appears exactly the same as before, as in Process 1 above.

So the question is, did Disk Utility create it as hardware RAID? Can it create it as software RAID too, and how to I tell the difference?

I assume Western Digital's app should have created it as a hardware RAID, as there is no point in making it a software RAID when the RAID hardware is present inside the drive.

(I am using OS X Mavericks if that makes any difference).

1 Answer 1


According to this article the "WD Thunderbolt Duo 6TB" misses - in contrast to the Pegasus2 series - one essential thing to be able to create a hardware RAID: a hardware RAID controller(-chip).

So whether you use Disk Utility or the native Western Digital tools you will only get a software RAID.

Even with an hardware RAID controller inside an arbitrary device, Disk Utility can't create/handle hardware RAIDs because it doesn't contain the necessary drivers to do so. AFAIK the only Apple tool for hardware RAIDs is the "RAID Admin" or "RAID Utility" accompanying the Mac Pro RAID Card and Xserve RAID Card.

  • I can't find any where even on WD's website and its specs whether the Thunderbolt Duo has software RAID or hardware RAID... but I assume this high end Thunderbolt drive has hardware RAID, but I could be wrong... I saw on this cnet review: cnet.com/products/wd-my-book-duo that even a My Book Duo has hardware RAID. But it might be true: I just found Thunderbolt Duo's product overview doesn't mention hardware RAID: wdc.com/wdproducts/library/AAG/ENG/4178-705323.pdf while My Book Duo does mention hardware RAID: wdc.com/wdproducts/library/AAG/ENG/4178-706423.pdf Aug 9, 2015 at 16:20
  • @user2334 The linked anantech article states that it doesn't contain a hardware controller chip
    – klanomath
    Aug 9, 2015 at 16:22
  • @user2334 The My Book Duo.pdf doesn't (or I can't find it) mention an hardware RAID controller. Only an hardware AES encrypted RAID. In my understanding that's an AES chip somewhere.
    – klanomath
    Aug 9, 2015 at 16:33
  • you can trust an anantech article in general? (it is not an article by a casual user?) By the way, I found that My Book Duo has "hardware RAID" stated in its user manual, while Thunderbolt Duo, My Cloud EX2, My Cloud Expert Series, My Cloud Business series, do not mention "hardware RAID" in its user manual Aug 9, 2015 at 16:33
  • @user2334 I took the anantech article as a hint.
    – klanomath
    Aug 9, 2015 at 16:45

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