Sonnet Allegro USB 3.0 card Speed Issue

Discussion in 'Mac Pro' started by flyman, Oct 11, 2016.

  1. flyman macrumors member

    Joined:
    Jan 28, 2004
    #1
    Hi Everyone,

    Ive just installed a Sonnet Allegro USB 3.0 4-Port card into my Mac Pro 3.1 and I'm a bit concerned with the read/write speed.
    I've put the card into slot 3 and attached a brand new never used 4TB WD My Book.
    The Black Magic speed test results are here...
    I would have thought it would be greater, what do you guys think?
    [​IMG]
     
  2. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #2
    That seems about right for a rotational hard drive with USB 3.0 interface.

    I get about 155-160MB/s connected to my USB 3.0 card in the Mac Pro, and slightly faster (170MB/s) when connected to the native USB 3.0 ports on the Mac Mini.

    Your numbers seem quite normal. If you are seeing much, much higher speeds somewhere else for USB 3.0 devices, it's probably an SSD. Or if it is a hard drive you might be mixing the units up because often speed is measured in megabits instead of megabytes, which is a big difference.
     
  3. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #3
    Very normal for HDD.
     
  4. flyman thread starter macrumors member

    Joined:
    Jan 28, 2004
    #4
    So do you think its worth moving into slot 2 where its x16 lanes?
     
  5. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #5
    Your card is not x16 (it's just a X1 card). Move to there won't help anything. And your speed test result was limiting by the HDD performance, nothing to do with the USB3.0 card.

    If you really need more speed, either get another HDD, run them in RAID 0, or upgrade to a SSD.
     
  6. flyman thread starter macrumors member

    Joined:
    Jan 28, 2004
    #6
  7. bent christian Suspended

    bent christian

    Joined:
    Nov 5, 2015
    #7
  8. h9826790, Oct 12, 2016
    Last edited: Oct 12, 2016

    h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #8
    The road (USB 3.0 card) has a 500km/h speed limit, and your car (HDD) can only do 150km/h. And you asked how come your car cannot run at 500km/h on that particular road. Do you know the why now?
     
  9. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #9
    Your hard drive can only output 155MB/s. It doesn't matter how much faster you make the USB interface or how many more PCIe lanes your slot has, because that is the best your hard drive can do.
     
  10. flyman thread starter macrumors member

    Joined:
    Jan 28, 2004
    #10
    I've got the picture now guys thanks clearing up my confusion!
     

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