External mass-storage (USB) disconnect on itself

Discussion in 'Mac Accessories' started by Mac2013orlater, Jun 13, 2015.

  1. Mac2013orlater macrumors member

    Feb 2, 2014
    It is about iMac 2013 Late with original Mavericks installation, latest release .9.5.

    Problems as described below are encountered since approx 10 months.
    I'd like to ask you if these are known problems or rather my local issue.

    There are several hard drives available, non-ssd.
    And enclosures of different types, some of them or of the kind a adapter SATA to USB 3.0
    others SATA to USB 2.0, yet others real enclosures.
    All drives are of same brand WD, but of different age. Some years old to quite new.

    Frequently while making a big file transfer (many MB or GB and of long duration) from or to or within such external they become disconnected in an unsolicited/unexpected fashion.
    If at such time they are logically inserted to os x
    the error message like "please eject correctly before disconnecting" pops up.
    The problems occur also if to use a non-OS X virtual machine hosted on this iMac
    for those data transfers.
    That means the transfer can start without problems and make a good progress
    for some duration but it aborts after some time due to issues described here.

    The experience that several hdd drives and several enclosures and OS X itself
    and the guest virtual machine are affected lets conclude me something with iMacs USB
    hardware or protocol stack might be wrong?

    How is your opinion?
  2. Mr. Retrofire macrumors 601

    Mr. Retrofire

    Mar 2, 2010
    I use this HDD/SSD docking station without problems (OS X 10.9.5, Mac mini 2012):
    --> http://www.amazon.com/dp/B00PFDT1B6/

    This enclosure/docking station uses the ASMedia ASM1153E USB 3.0 <--> SATA III bridge chip, which supports the UASP and the OS X HDD/SSD sleep functions.

    Older ASMedia chips which support SATA III drives are: ASM1053E and ASM1051E. If you buy enclosures/docks which use older ASMedia chips, make sure that the seller provides firmware updates for those chips. Plugable provides firmware updates for older ASMedia chips:
    --> http://plugable.com/drivers/hddockfirmware

    The ASM1153E has already the newest, compatible firmware.

    Inateck sells also "real" enclosures which use the ASM1153E:
    --> http://www.amazon.com/dp/B00UAA4J6G

    Regarding non-ASMedia chips: They are often unreliable, non-OS X compatible and do not support UASP.
  3. ColdCase macrumors 68030

    Feb 10, 2008
    USB devices are designed for the consumer market and are sent out without much testing. They do not comply with USB standards and the vendors could care less (not in their business model). Their quirks affect one operating system or another. So its just the nature of USB.

    There are a few vendors that take more pride in their work and sort things out better before selling them, but that means they are slow to market and more money... so folks don't buy them. They buy the cheap stuff an wonder why they are flakey.

    Vendors could get away with slip shot work with USB2, but USB3 is much more complex and full of details quick to market vendors overlook.

    Cables are notorious for giving one headaches.

    There are some well known brand that work well, but even then its hard to overcome the USB3 storage protocol deficiencies. They work just fine with other, less demanding type, applications.

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