External drives not mounting in 3 of 4 USB 3 ports

Discussion in 'iMac' started by PatrickNSF, Jan 16, 2016.

  1. PatrickNSF macrumors 6502

    PatrickNSF

    Joined:
    Jan 24, 2011
    #1
    I have a late 2015 iMac Retina. I have a number of USB-3 external drives (with and without separate power), and none of them will mount in 3 of the 4 USB-3 ports on the back if the iMac. They all mount fine in the left-most port (near the Thunderbolt ports). And they all mount fine when attached to the iMac by a USB-2 extension cable and the iMaccompanion USB extension, which claims to be USB-3. The same holds true for my USB-3 thumb drive. USB-2 devices are working fine.

    Any idea what could be causing this? I'm running the 10.11.4 beta, but am not sure if I experienced this behavior before upgrading. Thanks.
     
  2. Fishrrman macrumors G3

    Joined:
    Feb 20, 2009
    #2
    I'd take that in to an Apple Store and demonstrate the problem.

    Could be a software problem, but then again, could be a motherboard problem, covered under warranty.
     
  3. PatrickNSF thread starter macrumors 6502

    PatrickNSF

    Joined:
    Jan 24, 2011
    #3
    Thanks. I'm restoring the system back down to 10.11.2. If the problem persists we're off the the Apple store :-/
     
  4. Erdbeertorte macrumors demi-goddess

    Erdbeertorte

    Joined:
    May 20, 2015
    Location:
    Castle Grayskull, Eternia
    #4
    Seems to be a problem in every Beta since 10.11.1. I noticed the same with my first 27" Late 2015 iMac that I returned because I wanted a different configuration.
    Also the USB 3.0 thumb drive and SSD connected with a USB 3.0 cable to the one working port both ran at USB 2.0 speed only.

    I did not test it yet with my second iMac because until now I only used Thunderbolt for external disks. The only devices connected to USB are the Logitech transmitters for my mouse and keyboard.

    But I'll test the USB ports soon with 3.0 drives.
     
  5. PatrickNSF thread starter macrumors 6502

    PatrickNSF

    Joined:
    Jan 24, 2011
    #5
    Just finished restoring back down to 10.11.2 and all the ports are working with USB 3 drives again. Between this and losing the ability to sync my Garmin to my iPhone with the latest iOS beta, I'm pretty much done with betas for the foreseeable future :-/

    Will have to test transfer speeds later today. Thanks for all the help!
     
  6. Erdbeertorte macrumors demi-goddess

    Erdbeertorte

    Joined:
    May 20, 2015
    Location:
    Castle Grayskull, Eternia
    #6
    I just tested every ports with two USB 3.0 flash drives. Both of them were only recognized by the one next to the Thunderbolt ports.


    And here ist a speed test:

    Bildschirmfoto 2016-01-17 um 21.16.58.png

    For that one:

    Bildschirmfoto 2016-01-17 um 21.29.44.png


    I don't understand why this issue appears again and again in every Beta and never exists in a final version. o_O
     
  7. PatrickNSF thread starter macrumors 6502

    PatrickNSF

    Joined:
    Jan 24, 2011
    #7
    Thanks. I wasted too much time last night trying to figure out what was going on.

    I probably wouldn't have noticed, but I've been moving files from a thunderbolt Drobo I'm planning to ditch to some USB 3 drives, and I could only use the port closest to the thunderbolt port. This may also explain why the transfers have been so tortiously slow.

    If nothing else, this will give me some incentive to start researching thunderbolt enclosures...
     
  8. Erdbeertorte macrumors demi-goddess

    Erdbeertorte

    Joined:
    May 20, 2015
    Location:
    Castle Grayskull, Eternia
    #8
    I wonder if it's a reason to get a refund if you paid for 99€ for the Developer Program and they are not able to put all drivers for their new devices in the Betas since several months.

    Luckily I don't need USB 3.0 at the moment and everything else seems to work fine with 10.11.4 Beta 1.

    But I'll try what happens when I replace the USB 3.0 driver with the one from 10.11.2.
     

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