iMac + Thunderbolt GoFlex + SSD = Native SATA III speeds?

Discussion in 'iMac' started by appletechpro, Jul 19, 2012.

  1. appletechpro macrumors regular

    Jun 26, 2012
    When the new iMacs released I will be purchasing a 2011 model as my secondary machine. My intention is to purchase GoFlex TB adapter and use an external SATA III SSD as my boot volume -- can I expect native SATA III speeds despite the drive being external?

    I know that Thunderbolt is theoretically 10 Gbps each way, but I have no experience with real-world transfer rates.

    Thank you.
  2. Flunkyturtle macrumors 6502

    Dec 20, 2011
    I get around 360mb's read and around 200mb's write.

    If you search my user i put a video up showing the speeds and stuff :)


    that one
  3. appletechpro thread starter macrumors regular

    Jun 26, 2012
    Those are acceptable speeds... but come on Thunderbolt! SATA III is 6 Gbps... Thunderbolt is 10 Gbps... so it loses more than 40% throughput?!

    I was expecting better results.
  4. WesCole macrumors 6502a

    Jul 1, 2010
    I am thinking maybe the Seagate controller is the bottleneck. It is still new technology and this is the first thunderbolt adapter that Seagate has released, so it is bound to improve.
  5. dearlaserworks macrumors regular

    Apr 28, 2012
    Eastern Shore, USA
    Doesn't the GoFlex adapter have SATA II (3Gbps)?
  6. Rumpot macrumors newbie

    May 25, 2012
  7. appletechpro thread starter macrumors regular

    Jun 26, 2012
    That makes sense. Thanks for the explanation.
  8. omvs macrumors 6502

    May 15, 2011
    The normal STAE121 is SATA2 (I believe), but I've read 'desktop' STAE122 is SATA3. OTOH checking Flunkyturtle's post, it seems like he has the STAE121 but is reporting higher speeds - maybe they upgraded since the initial versions?

    Assymetric read/write speeds seem to suggest to me that the bottleneck is the SSD, not the adapter. But I'm just speculating - I only have a Vertex 2, which is 250MB read / 200MB/write and I get the same thing whether its internal or TB connected.
  9. Orlandoech macrumors 68040


    Jun 2, 2011
    Salt Lake City, UT
    I still think TB is so overpriced. Its absurd.
  10. rismay macrumors newbie

    Aug 24, 2012
    iMac + Thunderbolt GoFlex + SSD = SATA II Speeds

    Is this false advertising?

    On the cover you get all sorts of numbers that say, "20x USB speed and 2 Channels!"

    However, the drives themselves only deliver SATA II connection speeds. If we take your numbers seriously 360 MB/s is actually 2.8 Gb/s and right at the MAX 3.0 Gb/s of SATA II. The drive, the thunderbolt adapter and the SATA II connection are all working amazingly well and working at their limit. However, it is false advertising by Seagate that is causing all this confusion.

    Why doesn't it say anywhere on the box, "Max Speed is 3 Gb/s due to SATA II connector"?

    Also, I think most USB 3.0 connectors are using SATA I which is approximately 200 MB/s maximum.

    Can someone explain to me if I'm missing something?
  11. awair macrumors regular

    Sep 6, 2011
    Yes, it's false advertising...

    ... Because they only sell the GoFlex with 5400 or 7200 rpm drives. You can't get close to these transfer rates unless you use SSD.

    The transfer rates quoted are however for the 'bus' rate and assume use of multiple devices.

    If you were to use an SSD RAID-5 device, then you might find the bus limiting.

    Check out for a thorough brief on the subject.

    I've tried 'quick & dirty' speed tests and found that my GoFlex TB devices get no faster transfer than using FW800! Using USB3 produces similar results.

    The OWC cases produce slightly faster transfers, with a significant bump using RAID-0 (7200 rpm HDD) or SSD, or more especially eSATA.

    I feel cheated by the whole advertising of the GoFlex range, but do appreciate the convenience of alternate interfaces. I will now however be trying to source some empty GoFlex cases for a couple of 3rd-Party SSDs.

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