Transfer to external unusually slow

Discussion in 'Mac Pro' started by pureelite1, Oct 5, 2013.

  1. pureelite1 macrumors member

    Joined:
    Nov 9, 2009
    #1
    I've almost hit my 500GB limit on my Macbook Pro. As such i've decided to move a bunch of files, movies, pictures, old documents, old installation files onto my 1TB external. All the files i wish to move have been put into one folder on my desktop and i've dragged these onto the external hard drive. I'm using 2.0 but the speeds i'm getting is really slow. Its showing that this 140GB folder will take 2 DAYS to transfer. I checked my activity monitor under utilities and the disk activity is showing my write speed as 4MB/sec? This is unusually slow for USB 2.0. Im wondering is there a solution to this extremely slow transfer speed?
     
  2. sevoneone macrumors 6502

    Joined:
    May 16, 2010
    #2
    That is pretty slow. USB 2.0 will typically give you effective speeds of 25 to 35MB/s (200 to 280Mb/s). It is possible the drive is going bad, but how your external drive is formatted will have an impact on your speeds.

    Most drives, unless they are branded as "For Mac," come formatted FAT 32. FAT 32 is a very compatible format, but it is very old (Win95 old) and inefficient by modern standards. If your external drive is formatted this way, it is likely to be the cause of your slow write speeds.

    If wiping out all the data and reformatting on your external drive is an option, you'd be better off to reformat your drive:

    If you only use your external drive with your Mac, HFS+ is the best option as it will give you the best speeds. However, if you need to be able to access the data on the drive on a modern Windows computer (Win Vista, 7 or 8) without special software, your best bet would be to use exFAT. While not as fast as HSF+, exFAT performance on a Mac is much better than FAT 32.

    Lastly, if your Mac or hard drive has a faster connection, like FireWire 800, that will also help speed things up.
     
  3. Macsonic macrumors 65816

    Macsonic

    Joined:
    Sep 6, 2009
    Location:
    Earth
    #3
    It might be either your internal HD or external HD is failing or about to die. Years ago I had a drive with slow transfers and died later. Though in your case might be different. If you can isolate the problem by getting a second Mac or another external HD to pinpoint the source of the problem.
     
  4. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #4
    I've done tons of large USB 2.0 transfers back in the day and this does not surprise me at all. The main factor I saw was file size. Transferring one or two extremely large files was relatively fast. Transferring 10,000 small files that added up to a couple hundred gigabytes would take a day or more. A secondary factor was using 2.5" drive or a drive with slower rotational velocity, as this really compounds the problem.

    I found it was worth the effort to disassemble the external drive and plug it directly into one of the SATA bays. It's a little extra work, but saves an immense amount of time. If you find yourself needing to do this often, upgrade to a faster external interface such as USB 3.0, ESATA, Thunderbolt, or even FW800.

    I use exFAT and it seems okay for the most part. However, despite the fact that OS X can read and write to the exFAT volume, the Time Machine app can not back up that volume nor can it use it as a place to back up to.
     
  5. pureelite1 thread starter macrumors member

    Joined:
    Nov 9, 2009
    #5
    I think as the post above me stated, the amount of files contributed to it taking forever. I had roughly thousands of files that in total made 140GB. However the transfer occurred in 22 hours not the 2 days it initially stated which was relieving. Guess the estimated menu bar is notorious for lying
     
  6. Macsonic macrumors 65816

    Macsonic

    Joined:
    Sep 6, 2009
    Location:
    Earth
    #6
    Good to know the transfer went well. Normally the progress bar does not show the actual duration at the start of the transfer, then the duration shortens as the transfer progresses.
     

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