USB 3 external drive performance?

Discussion in 'OS X El Capitan (10.11)' started by Sanlitun, Jun 28, 2015.

  1. Sanlitun macrumors 6502


    Sep 19, 2014
    Anyone else experiencing very slow performance from external USB 3 storage? I know the release notes specify issues with USB 2 but say nothing about this.

    I have a SSD in an external USB 3 enclosure that I get 400 MB/s on my Macbook Pro but now on my nMP
    I am lucky to get 40 MB/s.

    Anyone else seeing this?
  2. Mr. Retrofire macrumors 601

    Mr. Retrofire

    Mar 2, 2010
    @Sanlitun: AFAIK, they update the USB drivers. Do not use 10.11 Developer Previews with your important USB devices!
  3. leventozler macrumors 6502

    Feb 18, 2009
    I get ~140MB write 360MB read (couple years old SSD)

    Checked another external SSD drive connected to a Trust USB 3.0 Hub and got ~36MB read/write. Check System Information > USB and make sure it's listed as USB 3.0 device.
  4. SG- macrumors regular


    Jun 8, 2015
    the release notes mention there's USB issues for last two builds.
  5. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    Transcend JetDrive enclosure here with an Apple SD256E SSD here (pulled from an Ivy Bridge retina MBP) - 330MB/s writes and 400MB/s reads.
  6. SoyCapitanSoyCapitan macrumors 68040


    Jul 4, 2015
    Looks like the USB driver isn't ready yet. Is there any hint it supports the latest XHCI 1.1 standard for USB 3.1 speed?
  7. MikhailT macrumors 601

    Nov 12, 2007
    No problems here with USB3 dual-bay chassis (Oyen Digital RAID v2), 350MB+ on both read/write.

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