USB 3 device being shown as USB 2 in Haswell iMac

Discussion in 'iMac' started by yjchua95, Oct 17, 2013.

  1. yjchua95 macrumors 604

    Joined:
    Apr 23, 2011
    Location:
    GVA, KUL, MEL (current), ZQN
    #1
    G'day y'all.

    I just got myself a USB 3.0 Archgon MH 3507HUB and was hoping to obtain transfer speeds of around 90-105 MB/s.

    However, I only got speeds of roughly 30MB/s.

    A quick check in System Information showed that the hub was being detected as a USB 2 device, although the product is specced with USB 3.

    I use a Haswell iMac with USB 3.0 ports.

    Attached is a screenshot.

    Is there a possibility that I've been had?
     

    Attached Files:

  2. gnasher729 macrumors P6

    gnasher729

    Joined:
    Nov 25, 2005
    #2
    Plug the drive directly into the iMac, not the hub.

    Edit: Just noticed, it is not just a hub but a hub with a built-in drive. In that case, my cunning plan won't work :-(
     
  3. yjchua95 thread starter macrumors 604

    Joined:
    Apr 23, 2011
    Location:
    GVA, KUL, MEL (current), ZQN
    #3
    Yea, it's a hub with a SATA connector to put a 3.5" or 2.5" hard drive into it. The hub itself also contains 3 USB 3 ports.

    Here's the hub: http://www.archgon.com/Web_en/MH-3507-II.html
     
  4. JustMartin macrumors 6502a

    Joined:
    Feb 28, 2012
    Location:
    UK
    #4
    Can you take out the drive and just have the hub plugged in? What does it say, then? And try adding a USB 3 device to the hub as well. I wonder if it's something odd with the drive dragging the hub down to USB2
     
  5. yjchua95 thread starter macrumors 604

    Joined:
    Apr 23, 2011
    Location:
    GVA, KUL, MEL (current), ZQN
    #5
    With nothing in the hub, it's still being identified as USB 2.0. Even with a Buffalo HD-PA1.0TU3 external drive connected to it, it still states USB 2.0.

    I already contacted the vendor about this, and they say they'll ship me a replacement.
     
  6. Bear macrumors G3

    Joined:
    Jul 23, 2002
    Location:
    Sol III - Terra
    #6
    This doesn't look like your issue, but I thought I'd point it out just in case. In Using USB 3 devices on Mac computers FAQ it states:
    So if a USB controller in a Mac sees a non USB 3.0 device first, data transfer speeds will be capped at USB 2.0 speeds. iMacs have 2 USB controllers.

    After some more thought, if it saw the keyboard first, that would limit the bus speed. Try plugging your disk into a different USB port on the iMac.
     

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