Very slow iMac after being unplugged accidentally

Discussion in 'iMac' started by AriKrook, Dec 26, 2015.

  1. AriKrook macrumors newbie

    Joined:
    Dec 26, 2015
    Location:
    Maasbree, Netherlands
    #1
    I accidentally unplugged my iMac while it was waking up from sleep. Since then it is dreadfully slow accessing the hard disk (Fusion drive). I formatted the hard drive and installed a new OS. even installing the OS (which should take 13 mins) takes an hour and a half. What could be wrong?
     
  2. MadDane macrumors 6502a

    Joined:
    Apr 5, 2015
    #2
    Which model do you have? Both size, year and so on. It could be the hard drive that has been damaged by the power shortage, since you mention you have reformatted it. Have you tried doing a hardware test?
     
  3. AriKrook thread starter macrumors newbie

    Joined:
    Dec 26, 2015
    Location:
    Maasbree, Netherlands
    #3
    Hi MadDane, Thanks for your reply. I found out what the problem was: the OWC SSD drive in my 3TB FusionDrive. I "disconnected" it from the HDD and noticed that the HDD acted normally and the SSD was extremely slow. Strange, because I could format it no problem and DiskUtility did not find any problems.
    How do I do the hardware test you recommended?
    By the way, my iMac is an early 2009 24" iMac running El Capitan. I upgraded it two years ago with a 3TB HDD and the 240 GB OWC SSD. It has been running beautifully (until yesterday).
     
  4. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #4
    Did you run the Disk Utility to check for errors and see the SMART status?

    Try running the AHT, to see if anything kicks out.

    If I were a betting man, I'd say the hard drive is having issues
     
  5. MadDane macrumors 6502a

    Joined:
    Apr 5, 2015
    #5
    I am glad you figured out what the issue is. You can run the Apple Hardware Test by holding down D when you start up the computer. There is a guide here how to do it: https://support.apple.com/en-ap/HT201257
     
  6. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #6
    Oops, my bad, looks like you posted this as I was posting mine. Glad to see that you figured it out :)
     
  7. AriKrook thread starter macrumors newbie

    Joined:
    Dec 26, 2015
    Location:
    Maasbree, Netherlands
    #7
    Hi maflynn, Thanks for replying. It appears to be the SSD. Installed OS on HDD and Mac runs fine.
    Diskutility shows no problems for SSD. I cannot run AHT.
    I try to copy a lot of data to the SSD. The first 2 GB seem to go OK (Time remaining: 4 hours), then write speed reduces to practically zero (Time remaining: 3 days).

    Do you know of an alternative to AHT?

    Thanks, Ari
     
  8. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #8
    DiskWarrior comes highly regarded.
     

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