iMac USB 3.0 Question

Discussion in 'iMac' started by jbg232, Feb 1, 2014.

  1. jbg232 macrumors 65816


    Oct 15, 2007
    I'm purchasing a new iMac and am worried about the wired keyboard. I am worried that the USB 2 interface will slow down the USB bridge. I have multiple USB 3 hard drives that I need to run at USB 3 speeds. From my understanding, the USB port speed is dependent on the 1st device the computer sees as apple states in their FAQ:
    Thus, if I have both my USB 3 hard drives and my USB 2 keyboard plugged in, is there any possibility that the drives will actually run at USB 2 speed?

    Anyone have any experience or answers to this question?
  2. macthefork macrumors 6502

    Feb 2, 2013
    They're talking about each of the four Ports. So, your USB 3 Drives will run at USB 3 speeds if they are the only thing plugged into a port. If you have a USB 2 keyboard plugged into one port and the USB 3 drive plugged into a second port, the USB 3 device will run at Usb 3 speeds.

    If you use a USB 3 hub, then this is where the USB 3 devices have to be plugged in first to get the proper speed on that port that the hub is plugged into.
  3. jbg232 thread starter macrumors 65816


    Oct 15, 2007
    So each port acts completely independently? I ask because usually 2 ports share the same bus internally at the motherboard level.
  4. macthefork macrumors 6502

    Feb 2, 2013
    On our Late 2012 iMac, I have one USB 2 hub plugged into one port (this I use for my older USB peripherals including the keyboard). The other three ports have USB 3 devices connected. All three USB 3 devices work at their proper speed.
  5. thedeske macrumors 6502a

    Feb 17, 2013
    Same for me - use a hub for wired key and mouse, printer - High speed USB drives attached to other ports. No problems
  6. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    Nope, each port is completely independent of each other.

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