External Hard Drive 100% when accessed

  1. Posts : 54
    Windows 10

    External Hard Drive 100% when accessed

    Every time I access my external hard drive, it jumps to 100% usage and stays that way for about 15 minutes.
    Ithink it is windows defender scanning it, but I'm not sure.

    even after the scan is complete, if I try to copy a file to it from a flash drive, it will jump up
    to full transfer speed for a second and then go to 0mb/s.. It sits there for a bit, then jumps back to full transfer speed for a few seconds and then dies back to 0mb/s.. An 800mb file took 20 minutes to copy, when it should have taken less than a minute.

    How can I tell what program is beating up the drive every time I access it?
    If it is windows defender, how can I tell it to NOT scan every time I access it?
      My Computer

  2. Macboatmaster's Avatar
    Posts : 874
    10, 8.1 and 7 all Professional versions, and Linux Mint

    1. It would assist if you could supply a little more detail of your system, rather than simply OS Windows 10

    Please help us to help you by filling in your System Specs
    from the link at the top when you click post new thread

    2. Windows Defender on Protection does not scan external drives
    In its normal settings - it only scans, files and folder etc that you open on that drive.

    3. If you see evidence of a scan OF THE ACTUAL DRIVE contents being made,
    Ithink it is windows defender scanning it, but I'm not sure.
    even after the scan is complete
    Please would you indicate where/how you have seen this.

    4. What please is the make and full model of the drive
    Its capacity and what free space is there on the drive please.
      My Computer

  3. Pejole2165's Avatar
    Posts : 747
    Windows 10 Pro 1909

    There could be several reasons for what you are seeing, defective media, corrupt file system, indexing, 3rd party apps accessing the drive.
    Using an app like CrystalDiskInfo can read the SMART values of the drive and possibly pick up on faults if they exists.
    The copy speed going up and down in a wave form can be down to the speed of the device being read from (slow reads would cause the write buffer to empty quicker than it was filling up), the speed of the device being written to (a slow write device would cause the read speed to drop while waiting for the write cache to empty), whether Windows disk caching is used or a 3rd party caching app and the cache size of the writing device, the copy speed is also affected by file sizes, a single large file will appear to write at a higher speed since sequential speed is always higher, smaller files will appear to have a slower write speed as the files may need to be written across a wider area of the disk (random access speed) you would also see this wave effect due to defective media and file system errors. It could also be down to using Windows generic drivers over motherboard manufacturers specific drivers.
    It is also possible for malware or viruses to cause high access times as they propagate to removable media, not saying this is happening, but any unusual activity is a red flag.
    Really there could be a lot of different reasons.
    Use Task Manager to see which task is causing the high usage. Disable all unneeded start up programs and/ or start in safe mode to test if the high usage continues.
    Try creating a test account to see if the issue persists.
    And finally as Macboatmaster says, more info and detail is needed.
      My Computer

  4. Berton's Avatar
    Posts : 10,582
    Win10 Pro Versions 2004 and 2009/20H2, Win10 Pro IP_Dev, Win10 Home 1909

    3DPiper said:
    An 800mb file took 20 minutes to copy, when it should have taken less than a minute.
    mb or Mb is Megabit while MB is MegaByte [8bits = 1Byte]. 800MB = 838,860,800 Bytes x 8 bits = 6,710,886,400 bits
    Transfer speeds are usually measured as per second in bps, Kbps, Mbps.
    So 800 is a larger number for most movies and will take awhile to download or Copy or Move. Most of the videos I have downloaded have been between 200MB and 600MB and usually play an hour twenty minutes to two hours thirty minutes.
    Transferring data from an internal drive to an external drive takes longer than if both drives are internal.
      My Computers


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