USB Disc mounting issues

Discussion in 'MacBook Pro' started by ourmanontheM62, Apr 1, 2015.

  1. ourmanontheM62 macrumors newbie

    Joined:
    Nov 24, 2013
    #1
    Bit of a head-scratcher this.

    Have an Akasa USB3 enclosure, and migrated my time machine backup onto this from a WD MyBook over the weekend, which worked fine.

    Now the data rate is very, very slow - I *think* the disc has mounted as USB 1.1 (using a legacy cable, as my early 2011 MBP doesn't support USB 3).

    Anyone any thoughts as to how I can 'force' the disc to mount as USB 2.0? My Google-fu is not living up to expectations.

    Thanks,

    Andy
     
  2. Samuelsan2001 macrumors 603

    Joined:
    Oct 24, 2013
    #2
    What hard disk have you got in it???


    Not a lot of use having a USB 3 connection if you have a slow old hard disk in there!!!
     
  3. ourmanontheM62 thread starter macrumors newbie

    Joined:
    Nov 24, 2013
    #3
    It's not, it's a SATA III WD Green. However, that's not the issue - the issue is that the USB caddy doesn't appear to have mounted as USB 2 (or at least the data rates are painfully slow).

    Didn't see much point in buying a non-USB 3 drive, even though my computer doesn't support this; may replace within the next 12 months...
     
  4. Samuelsan2001 macrumors 603

    Joined:
    Oct 24, 2013
    #4
    Well

    The WD green is quite a slow drive but shouldn't b3e too bad what sort of speeds do you get on Black magic disk test??
     
  5. ourmanontheM62 thread starter macrumors newbie

    Joined:
    Nov 24, 2013
    #5
    Haven't tried Blackmagic, to be honest, and I'm not expecting miracles as it's over USB 2. Shouldn't take 9h to do a TM backup though.
     
  6. Samuelsan2001 macrumors 603

    Joined:
    Oct 24, 2013
    #6
    Actually thats not unexpected.....

    How much data??

    And that estimate will usually come down.
     
  7. ourmanontheM62 thread starter macrumors newbie

    Joined:
    Nov 24, 2013
    #7
    An incremental backup - about 3Gb?

    Have given up and reformatted; now doing a full TM backup (have never needed to rescue from the past anyway, tbh) - saying 8h for 360Gb which doesn't seem shocking.
     
  8. Samuelsan2001 macrumors 603

    Joined:
    Oct 24, 2013
    #8
    Yeah that sounds about right

    For 3gb that is shocking.

    For 360gb that is about right I'm afraid. That WD green gets fairly slow write speeds....

    http://www.storagereview.com/western_digital_caviar_green_2tb_review_wd20ears


    they range from 50 - 120MB/s write speeds.
     
  9. ourmanontheM62 thread starter macrumors newbie

    Joined:
    Nov 24, 2013
    #9
    I can live with fairly slow write speeds for what is, after all, a drive for incremental backups. 3Gb in 9h... no.
     
  10. ourmanontheM62 thread starter macrumors newbie

    Joined:
    Nov 24, 2013
    #10
    The oddness continues.

    After reformatting, I can get it to back up each of the computers once (one 2011 MBP running 10.10, one 2008 MB running 10.6.8).

    When I then swap the drives between computers again, I ger an error saying OSX cannot repair the disk - anyone any suggestions what's going on? Have I got a bad disk, or is this some sort of software issue (and how can I fix it)? Drive is a WD Green 3Gb as above, in an Akasa X31 USB enclosure.
     

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