USB 4-Port behavior ????

Discussion in 'iMac' started by Spike88, Aug 17, 2010.

  1. Spike88 macrumors 6502a

    Jan 25, 2010
    My wife's new iMac 21.5" 3.2 GHZ is configured as:
    - USB Port 1 - APC Backup Control cable.
    - USB Port 2 - HP Printer cable.
    - USB Port 3 - "wired" larger size keyboard.
    - USB Port 4 - USB 2.0 - 4 port Hub (with 16" long cable).

    For picture of this hub, see "under left side iMac screen" at: iMac system/After-1.jpg

    On this USB 2.0 4-port hub, I connected a 8 GB USB stick and copied over a large .AVI movie file. Its copy status screen showed 15 minutes to copy the file over. I checked the USB product manual and it is USB 2.0 rated. But, it also didn't state if Win or Mac compatible (if this matters).

    Afterwards, I then removed this USB 4-port hub and connected a "direct" USB extension cable. Then, connected my USB stick to it. Copied over the same large .AVI file and it copied under 2 minutes. WOW. Much, much faster.


    With above in mind.... Does a USB hub must be documented with MAC OS "compatible"? Or, does the USB Port perform B/W splitting (re: equal amounts to each port)? Or, is USB hubs share the same physical B/W and my 4-port USB hub isn' perfoming as it should?

  2. Jimmdean macrumors 6502

    Mar 21, 2007
    it's most likely a power issue - if the usb hub does not have a separate power supply, then it is getting its power through the main port you have it plugged in to, then splitting that out to its own ports. Your flash drive probably just isn't getting enough juice. I'd put the printer cable and maybe the UPS cable in that hub (since they don't need power) and leave a couple of the main ports open for your other needs...
  3. bobr1952 macrumors 68020


    Jan 21, 2008
    Melbourne, FL
    I'd recommend a powered hub--I have a pretty inexpensive 5-port hub--but it is powered and has worked fine with multiple external drives connected to it for several years. I plug my iPhone into it too with no issues.
  4. Spike88 thread starter macrumors 6502a

    Jan 25, 2010
    Thanks for your feedback.

    My 4-Port USB hub does have a "power hole" on the back of it. It has printed power specs as well. Next time I'm at my local dollar store, I'll buy a universal Power Adaptor for it. Thus, getting a "powered" 4-port hub.

    Having a 4 Port hub under the iMac stand is easy access for our many USB "wired" items. re: Ipod Touch devices, USB Sticks, Digitial Camera cables (that have older / large size memory card, etc. etc.)

    Thanks for your "power it up" suggestion. I'll give it a try....


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