slow usb transfer

Discussion in 'Mac Accessories' started by koswo, Mar 21, 2006.

  1. koswo macrumors member

    Joined:
    Oct 7, 2004
    Location:
    Belgium
    #1
    Hi, I copied about 30 GB of data (photos, music and downloaded files) to my external hard disk. The copy operation took about 9 hours! It's a USB 2.0 drive (Lacie, 250 GB) connected to a passive 4-port USB HUB (from HP, I got it for free on a conference) which is connected to the rear USB port of my Intel iMac. Can anyone explain why the copy operation took so long, since the transfer speed of USB 2.0 is about 57 MB/sec... Could it be because the hub isn't self-powered?
     
  2. mad jew Moderator emeritus

    mad jew

    Joined:
    Apr 3, 2004
    Location:
    Adelaide, Australia
    #2
    Have you tried transferring data without the hub? :)
     
  3. revenuee macrumors 68020

    revenuee

    Joined:
    Sep 13, 2003
    Location:
    A place where i am supreme emporer
    #3
    do USB hubs work like network hubs?

    where the entire network slows down to the speed of the slowest connection

    ie ... a 100 base/t ethernet will slow down to 10 base/t if one of the computers connected has 100 base/t card?

    my point being -- is there anything on the USB hub connected, running at USB 1.1 that would slow the whole thing down.
     
  4. elisha cuthbert macrumors 6502a

    elisha cuthbert

    Joined:
    Feb 25, 2006
    Location:
    Melbourne
    #4
    This happened to my a while ago on my ibook and i just unplugged the hud and then pluged the ehd into a usb port and it worked alot faster
     
  5. Dunepilot macrumors 6502a

    Dunepilot

    Joined:
    Feb 25, 2002
    Location:
    UK
    #5
    Oh yeah, just one word of warning, if it's possible to power the hub, be very careful that you use the right kind of power supply for it. The bassist in my band managed to destroy a hub, his USB2 audio interface and his MacMini's logic board by plugging in a power supply for the hub that was a bit too high for safety. Luckily he's just had them all replaced by the manufacturers for free ... needless to say he kept schtum about the power supply situation.
     
  6. andiwm2003 macrumors 601

    andiwm2003

    Joined:
    Mar 29, 2004
    Location:
    Boston, MA
    #6
    when i use my unpowered USB hub with my LaCie HD the speed goes down. it feels like USB 1.1. When i transfer directly from the mac it works just fine.
     
  7. mfacey macrumors 65816

    mfacey

    Joined:
    Feb 1, 2004
    Location:
    Netherlands
    #7
    Bear in mind that your hub has to be USB 2.0 compatible as well. And the cable to your mac has to be USB 2 certified!

    If that's not the case for you, then you're crippling the performance of your data transfers to usb 1.1.
     
  8. Mitthrawnuruodo Moderator emeritus

    Mitthrawnuruodo

    Joined:
    Mar 10, 2004
    Location:
    Bergen, Norway
    #8
    And not just USB 2, but High speed (Hi-Speed) USB 2.... there actually is a low speed version of USB2 that some (cheaper) devices might have (although rare)... :rolleyes:
     
  9. mfacey macrumors 65816

    mfacey

    Joined:
    Feb 1, 2004
    Location:
    Netherlands
    #9
    Indeed! Forgot about that! :rolleyes:
     
  10. trogdor! macrumors regular

    Joined:
    Mar 7, 2006
    #10
    Yep, check and make sure the hub is 2.0 compatible.
     

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