New iMac 27" and USB3: Something must be wrong here (speed)

Discussion in 'iMac' started by loicg, Feb 9, 2013.

  1. macrumors newbie

    Joined:
    Jan 23, 2013
    #1
    Hi folks,

    I'm using for a couple of weeks the new imac 27 (basic one), and I bought an ICY BOX IB-120CL-U3 and 2 WD green caviar 3To for backup purposes.

    I use superduper software to start the first backup copy. I am very surprise to see these figures below: effective speed below 15MB and "max speed" according to system report being 12MB... Any idea? That's annoying as I was seeking for this USB3 speed.

    Here the speed in superduper, from the imac drive to the backup drive:
    [​IMG]

    Here the system report:
    [​IMG]

    [​IMG]

    (The ICY BOX is meant to be UBS3 compatible and I used the blue cable that was in the package.)

    Thanks for your help!
     
  2. thread starter macrumors newbie

    Joined:
    Jan 23, 2013
    #2
    After a second try, the max speed I got was much better, nearly 60 MB/sec, not more but looks fine to me.
     
  3. macrumors regular

    Joined:
    Dec 29, 2007
    Location:
    Cape Cod, MA
    #3
    the WD greens, if i remember correctly are for low power usage and not speed... but glad you worked it out...
     
  4. thread starter macrumors newbie

    Joined:
    Jan 23, 2013
    #4
    True, 5400rpm, their purpose is more for backup uses, but I expected something better than USB 1.1 :)
     
  5. macrumors 604

    Joined:
    Mar 26, 2008
    Location:
    West Suburban Boston Ma
    #5
    IIRC, SuperDuper on the 2nd try is copying a lot less data, and reports the transfer higher even though the actual speed is the same. ie it's "copying" say 1 GB, but actually only copies 100 MB. Don't depend on SuperDuper's statement of effective speed.
     

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