USB drives start connection times different?

Discussion in 'Computing and Networks' started by Kardo22, Nov 28, 2014.

  1. Kardo22

    Thread Starter New Member

    Mar 12, 2014
    26
    0
    Hi
    In my workplace I was asked a question and I'm quite unable to answer.
    A worker ask why 1 USB thumb drive takes longer than other to get connected (about 5 seconds).
    We have a processor board with network connectivity that we instal CAN and serial port drivers from an USB thumb drive. Recently 1 USB drive dropped dead, so we switched it to another (same software).
    It used to take about 2-3 seconds for the processor board to indicate the USB was connected but now it takes nearly 10s.
    What could make such a difference?
    I've also noticed similar differences in windows, some USB drives take a lot longer to get recognized (even if driver is already installed). Is the software to initiate connection so different?

    Thanks
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,179
    1,799
    When a USB device is introduced there is a process called enumeration that takes place. It is a non-deterministic series of questions and answers that is used to determine the capabilities and features of the device. Would you really expect ALL manufacturers to implement their devices in the identical way? If so, you have a naive view of commerce in the global environment.
     
    RamaD likes this.
  3. Kardo22

    Thread Starter New Member

    Mar 12, 2014
    26
    0
    I get that there are differences how USB sticks communicate. Is it determined in its driver?
    But what makes for so big differences, some take a couple of seconds, others nearly 30s?
     
  4. tom_s

    Member

    Jun 27, 2014
    285
    333
    hi, question is already answered in post #2

    putting it into simple terms, you get what you pay for.

    example, one of my clients bought from china some client giveaway 8gb memory sticks for christmas last year. they looked ok until you plugged them into a usb port. same problem as your varying detect issue, and painfully slow to put data (if at all) on them. all 200 went straight in the bin.

    you have better quality control with respectable name brands,
     
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