iMac Painfully Slow Since Lion Upgrade

Discussion in 'iMac' started by effectivepull, Aug 9, 2011.

  1. effectivepull macrumors newbie

    Jul 22, 2011

    I recently upgraded from Snow Leopard to Lion and my iMac is now painfully slow. Sometimes it takes Photoshop CS5 multiple minutes (spinning beach ball) to process things that took seconds before the upgrade. It's not only isolated to Photoshop. I'm also having difficulties with Firefox (ver. 5.0.1), Aperture 3 (ver. 3.1.3) and other programs.

    I've tried repairing disk permissions but I didn't see a speed boost.

    Here are the specs for my iMac: Processor: 2.66 GHZ Intel Core i5
    Memory: 8GB 1067 MHz DDR3.

    Anyone have any new suggestions? Or is this something I should expect for a iMac that is a few years old?

  2. Abazigal macrumors G3


    Jul 18, 2011
    My guess is that something went wrong during your upgrade. Not sure how you can do a reinstall without a clean install (erase everything and fresh install lion) though.
  3. velocityg4 macrumors 601


    Dec 19, 2004
    Have you rebooted since the upgrade completed? My Macbook was painfully slow when it first booted after the upgrade. Once I rebooted, with the restore programs option unchecked, it returned to normal.
  4. effectivepull thread starter macrumors newbie

    Jul 22, 2011
    @Abazigal - I feared the whole reinstall via Snow Leopard then to Lion. I'm hoping there was something that I was missing as I have only been using Macs for a few years.

    @velictyg4 - I've rebooted many times since upgrade and no luck.

    Any other suggestions or input would be greatly appreciated.
  5. c613m macrumors 6502


    Aug 9, 2011
    I would suggest creating a Lion USB and do a clean install of Lion. When I upgraded from Snow Leopard it wasn't slow, however now after a clean install of everything it's extremely fast. Was worth the couple of hours it took to get everything back the way it was. I didn't want to restore from a Time Machine backup.
  6. Taz Mangus macrumors 68040

    Taz Mangus

    Mar 10, 2011
    Before you go the clean install route, try booting into the restore partition and do a Lion restore. This will just do a overwrite of the system as it is. If that does not work then I suggest you do a clean install after you do a backup.

    EDIT: Also open the console app and see if there are any crash logs. Maybe you have a third party app which is causing the slow down due to being incompatible with Lion.
  7. MrMoore macrumors 6502

    Nov 2, 2006
    Arlington Heights,IL
    Could it be that the Spotlight Index is still rebuilding? When the Lion upgraded is completed, it rebuilds the index. You can see if there is a dot in the magnifying glass. The rebuilding can cause slowness.
  8. danp macrumors member

    Sep 26, 2005
    Cambridge, UK
    This is definitely something to consider and rule out. This is a well documented cause of performance degradation following an install of Lion. Once that is complete, I would not expect you to notice any performance change (good or bad) versus Snow Leopard.

    As you state that the performance drop is across the board, have you checked Activity Monitor to ascertain if any other applications are hogging CPU time?
  9. accessoriesguy macrumors 6502a

    Jul 8, 2011
    worse case, you may have to do a clean install, that's what I am planning to do anyhow.
  10. effectivepull thread starter macrumors newbie

    Jul 22, 2011
    Thank you all so much for your thoughtful responses. This forum is awesome and a wealth of information.

    I've ruled out Spotlight rebuilding, there does not appear to be any resources suck by any app in the Activity Monitor, and the console app does not reveal any crashes - that I can see anyway.

    I will continue to monitor this string for the next few days and if the problem doesn't resolve, I'll to do a Lion restore via restore partition. If that doesn't work, then it will be a complete wipe and reinstall (I'm dreading having to re-reference all my photos in Aperture!).

    Thanks again and please keep any suggestions you have coming!
  11. rufhausen macrumors regular

    Jul 5, 2007
    Littleton, CO
    Try cleaning out the cache folders as described here:
    This is presented as an Aperture-specific fix, but it made a big difference for me system wide when I used Migration Assistant to move from an old MBP to a new iMac. I've made it standard practice now then I do an upgrade or use MA.
  12. effectivepull thread starter macrumors newbie

    Jul 22, 2011
    I ended up wiping the drive and reinstalling SL. BLISS!

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