USB 3.0 slow on my brand new iMac

Discussion in 'iMac' started by tarsierspectral, May 19, 2013.

  1. tarsierspectral macrumors regular

    Joined:
    Aug 13, 2010
    #1
    Why are the USB 3.0 ports so slow on my brand new iMac? I am transfarring from an SD card using Delkin Devices card reader and first it takes about 30sec to about 1min for the card to appear on my desktop and then it gives me the time of like 8 hours to transfer 6GB than it reduces and ends up being way less BUT when I plug the same reader, the same card to my Mac Pro which is 3 years old and doesn't even support USB 3.0 the card shows up on the desktop immediately and I am able to open it and look at files and the transfer is super fast. What's wrong with my new machine?
     
  2. iamgalactic macrumors regular

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    Apr 21, 2010
    #2
    what speed is your card reader? it may be USB 2 - which means it can't get USB 3 speeds. also, there may be some backward compatibility issues with that device...

    go to apple>about this mac>system report>USB

    is your card reader under the USB 3.0 section?
     
  3. tarsierspectral thread starter macrumors regular

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    Aug 13, 2010
    #3
  4. Nuke61 macrumors 6502

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    Columbia, SC
    #4
  5. tarsierspectral thread starter macrumors regular

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    Aug 13, 2010
    #5
    But it works fine on Mac Pro
     
  6. gnasher729 macrumors P6

    gnasher729

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    Nov 25, 2005
    #6
    It's most likely a matter of the SD card itself. USB 2 can transmit up to about 35 Megabyte per second on a new Mac; if something is slower than that then it is a problem with the reader or the card. If the card is slow, then USB 3.0 won't help one bit, and a fast card reader won't help either.

    Basically, your card can do X megabyte per second, your card reader can do Y megabyte per second, the Mac can do 35 megabyte per second with USB 2 and a lot more with USB 3, and your actual speed is the slowest of the three.
     
  7. tarsierspectral thread starter macrumors regular

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    Aug 13, 2010
    #7
    But why is it fine on my Mac Pro?
     
  8. PJM82 macrumors member

    PJM82

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    Apr 28, 2013
    Location:
    United Kingdom
    #8
    Different chipsets, your Mac Pro is an older generation. Most likely this.
     
  9. tarsierspectral thread starter macrumors regular

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    Aug 13, 2010
    #9
    So older generation is better?
     
  10. jmhart, May 19, 2013
    Last edited: May 19, 2013

    jmhart macrumors regular

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    Jun 14, 2012
    #10
    I'd try a different USB 3.0 reader...if possible one that is Apple tested and recommended. Not all bridge chipsets are equally compatible with a given hardware and driver configuration.
     
  11. Nuke61 macrumors 6502

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    Jan 18, 2013
    Location:
    Columbia, SC
    #11
    But it doesn't work fine on your newMac. Does the built-in SD card reader work well? If it does, you could use that while you're working on a solution with the Delkin. But i still say contact Delkin and see if they have a firmware update.

    There's a reviewer on Amazon who said this reader was super slow on his Mac, like USB 1.0 speed. http://www.amazon.com/Delkin-Univer...?ie=UTF8&filterBy=addOneStar&showViewpoints=0
     
  12. Raima macrumors 6502

    Joined:
    Jan 21, 2010
    #12
    Can you also confirm you're using a USB3 cable to connect the device to the iMac?

    You can generally tell a USB3 cable by the blue connections. USB3 cable has more wire channels internally than a USB2 cable.

    Using a USB2 cable to connect to a USB3 device may create undesired results.
     
  13. thedeske macrumors 6502a

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    Feb 17, 2013
    #13
    Plug it in direct. Duh - Sorry, but obvious first thing to do before assuming the new iMac is slow.
     
  14. iamgalactic macrumors regular

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    Apr 21, 2010
    #14
    plug in the card reader and do this:

    go to apple>about this mac>system report>USB

    is your card reader under the USB 3.0 section?
     
  15. PJM82 macrumors member

    PJM82

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    Apr 28, 2013
    Location:
    United Kingdom
    #15
    In some cases yes. The chipsets are different so will have different quirks and the drivers will differ. Its almost like running Windows now. On one of my PCs my USB 3.0 stick works just fine, on the other it doesn't. Same version of Windows, similar hardware specs.

    This is worth a try. If its not possible or still doesn't work then USB 3.0 card readers aren't that expensive, I would consider trying another one. Any other USB 3.0 devices you can try?
     

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