Unveiled at the late January 2012 Macworld Expo, WD's Thunderbolt Duo began shipping in mid-March, in both 4 TByte and 6 TByte versions:

This two-drive, two-Thunderbolt-port enclosure is fanless, as with the Seagate GoFlex Desk, thereby explaining WD's decision to go with Caviar Green "IntelliPower" HDDs instead of the faster-spinning but also hotter-running Caviar Blue, Caviar Black or VelociRaptor counterparts. Specifically, my review 6 TByte unit contained two WD30EZRX HDDs, with 64 MByte caches and 6 Gbps SATA interfaces. WD, as you may already know, has long declined to reveal the RPM range over which its Caviar Green HDDs operate; a specific RPM at any particular time is dependent on both access requirements and sensed operating temperature.

As with the Seagate Thunderbolt Adapter, WD does not include a Thunderbolt cable with the Thunderbolt Duo adapter. And don't bother trying to swap out the included HDDs for SSDs. In addition to asking me to not disassemble the enclosure in order to see what was inside, my PR contact at WD warned me, "the drive will not recognize anything other than the WD Caviar Green drives that it is qualified and designed for." And the stickers stuck to the drives also indicated as such:

Nonetheless, I attempted to do so anyway, wanting to stress-test the transfer rate capability of the enclosure's circuitry and software, potentially beyond that of the rotating media inside. Swapping out drives is a fairly simple process; the topside face is held in place by a spring-loaded latch:

below that, a thumbscrew-constrained metal plate:

Remove both, and you can then lift a drive straight out:

I temporarily replaced both 3.5" Caviar Green HDDs with 2.5" 256 GByte Micron C400 SSDs, whose light weight, in combination with the vertical mounting orientation, enabled them to reliably remain in place using only the SATA and power connectors:

But a variety of error and warning messages indicated to me that my PR contact's guidance had reality at its basis; WD seems to be polling the drives' firmware upon power-up and blocking usage when it discerns invalid manufacturer and product codes:

The bay A error message isn't strictly accurate; the SSDs work fine, and both re-inserting the one in bay A and swapping their respective locations produced no change. This particular message seems to just be the functional equivalent of the 'incompatible drive' notification for bay B.

Seagate's GoFlex Desk with Thunderbolt Adapter Software RAID
Comments Locked


View All Comments

  • Grizzlebee - Sunday, May 13, 2012 - link

    "Not surprisingly, the RAID 0 striped results were roughly 2x faster than those either accessing a single drive at a time (JBOD and concatenated) or both drives simultaneously but in a mirrored fashion (RAID 1). "

    Judging from the table data, you meant to say 1x faster or twice as fast. Great review though.
  • bdipert - Sunday, May 13, 2012 - link

    Good point, Grizzlebee, I'll tweak the text. Thanks for the kudos!
  • Articuno - Sunday, May 13, 2012 - link

    USB has over two decades of backwards compatibility, has no patents controlling it, the royalties are optional and it's fast enough for 90% of tasks it's used for today. Thunderbolt may be faster, but it costs more in every aspect, has EXTREMELY low adoption rate across the board and still can't manage the "one cable for everything" idea Apple originally helped create it for because it uses copper wiring instead of fiber optics.
  • repoman27 - Monday, May 14, 2012 - link

    The high cost of Thunderbolt devices compared to mainstream consumer gear has nothing to do with patents or royalties. It's actually insanely cheap compared to any other 20 or more Gbps, full-duplex over a single cable technology. There are plenty of people out there for whom having this type of technology is a serious aid to their workflow.

    Point to another first generation I/O technology that had a higher adoption rate in its first 12 months.

    Apple never espoused a "one cable for everything" idea, as is clearly evidenced by the fact that the Thunderbolt ports they added to the 2011 Macs are right next to... well, a bunch of other ports, including USB.

    How exactly would Thunderbolt be better if it used fiber optics? For the short cable runs most users typically require, copper is still king. You can use a fiber optic cable with current Thunderbolt controllers if you like, it'll just cost more.

    If the performance gain you get from a Thunderbolt enabled workflow isn't worth the couple hundred dollars extra that it would cost you, then don't shell out for it. But at least recognize that for some people, it's well worth it.

    Just because you don't use something yourself, does not make it a failure. I've never personally needed to drive a semi-trailer truck, but I'm sure glad others do every day, and I would hardly categorize the entire class of vehicles as a failure. You may not realize how ubiquitous 1394 is, but rest assured, it continues to be quite useful to many folks out there.
  • philipma1957 - Sunday, May 13, 2012 - link

    If you own a mac you have 3 options.

    1) seagate thunderbolt 2.5 inch adapter apple cable and a 256gb ssd if sata 3 any larger has stability problems. I use a mushkin 240gb and a crucial m4 256gb fast stable use as os drive with mac minis. cost if you got the deal with the crucials at 199 the cost is 350 for a stable external boot drive.

    2) next a lacie little big disk pull the 500gb drives and put in a pair of samsung series 810 ssds 256gb. in fact I am typing on that setup right now. cost 400 for the little big disk 50 cable and 600 for the ssds. 1050 and I sold the spare 500gb hdds. for 150 net is 900. pull the insane fan sounds like a effing mosquito on steroids. this was 900.

    now you could build this for less if you got the 256gb crucials at 200. this would be 850. this is an outstanding os drive. rock steady in raid0

    3) last buy the pegasus r6 use the software to run 2 raid0 setups. one with a raid0 for lion one with a raid0 for boot camp the other 2 drives are backup use it with a mac mini server or an imac cost is 1500 plus the ssds 4 of the crucials would have been 2300.

    these units tested today are pretty much not getting what t-bolt is good for external ssd boot drive along with a raid0 for storage. they all run hot and they may not be stable. (time will tell) any of the setups I mention work and work well. they have ended the iMac my internal drive is trapped problem. Now usb3 would be almost as good for the 3 above it would only lag a lot to the pegasus.
  • StormyParis - Sunday, May 13, 2012 - link

    Can we please have the CPU load info? I remember my PC becoming so jerky as to be unusable during heavy USB2 I/O in the early days.
  • bdipert - Sunday, May 13, 2012 - link

    Hi StormyParis, I mention CPU load to some degree on the 'Software RAID' page, related to the Thunderbolt Duo. Suffice it to say that in RAID 0 mode, the incremental CPU load specifically due to software RAID was miniscule (a few percentage points of one of the four 'cores'...two physical cores, further doubled to 'four' courtesy of HyperThreading support in the CPU), and in non-RAID modes for both the Seagate and WD drives, it was imperceptible for Thunderbolt alone.
  • isulzer - Monday, May 14, 2012 - link

    Its a permissions issue.

    The app cannot write to the root directory, so it fails.

    Easiest way to get around this (if insecure) is to grant all users write access to the drive.
  • bdipert - Monday, May 14, 2012 - link

    Thanks for the feedback, isulzer, but the MacBook Pro SSD (which I was able to successfully run AJA on) is also that particular system's boot drive. Is the particular O/S part of the reason for the issue? The MBP runs Snow Leopard, the Mac mini runs Lion
  • isulzer - Monday, May 14, 2012 - link

    In lion and mountain lion, permissions on the boot drive are slightly different. Only System has write access. Everyone else has read only. So if you try to write a file to \ in Lion, you will have to authenticate.

Log in

Don't have an account? Sign up now