Booting does not clear RAM

Discussion in 'iMac' started by Mac09, Jul 3, 2013.

  1. macrumors newbie

    Jul 3, 2013
    My Mac has started freezing and Activity Monitor shows that most of the RAM is "wired" (5.3 GB out of 8 GB). There are no CPU processes listed that are using that much memory.

    As of now I can only boot in safe mode, and unfortunately, booting is not clearing the RAM. After safe boot, Activity Monitor always shows that 5.3 GB of memory is still wired.

    Up until yesterday cleaning the caches seemed to allow a normal restart with cleared RAM, but now that doesn't work. I've downloaded and run a couple of "memory cleaner" apps but they don't help either. I probably need to do a clean restore of my Mac to get it back to normal, but would like to update my backups before doing so. However to do that, I will need to clear the RAM so that I can restart the Mac normally.

    Am I going to have to do the best I can in safe mode, or does anyone know of a way that I can force the RAM to clear?

  2. macrumors 6502

    Oct 11, 2012
    When your Mac restarts, it begins with essentially all of the RAM free. The EFI boot firmware uses some, OS X uses some, and all the applications and processes that start automatically use some. By the time you look at Activity Monitor, lots of memory is used.

    What version of OS are you running? Modern applications running on the latest OS keep running across an OS restart. (Actually the OS stops them as it shuts down, and restarts them automatically when it restarts.) Just because an application doesn't have any visible windows does NOT mean it's not running and using memory.

    Activity Monitor should show you the application(s) that are using lots of memory. Are you sure you don't have some kind of filter enabled that hides some of the processes?

    "Cleaning caches" is a vague and usually useless maintenance activity. Exactly what did you do that you thought made more memory available?

    Restoring your system from backup won't help (unless your backup doesn't have much software installed, so nothing much will run when you restart the computer.)
  3. thread starter macrumors newbie

    Jul 3, 2013
    I generally quit all apps before restarting, and in the past was seeing @75% free memory (6 GB out of 8 GB). However, since having these freezing problems, only about 25% of RAM is free after safe boot, and no apps listed in Activity Monitor are using a significant amount of memory.
    I am using OS X 10.8.4.

    In my troubleshooting research I learned of a command called kextstat which lists the processes using wired memory, and the process using the most memory is this:
    using this much memory:

    In regards to cache cleaning before restart, it seemed for a while to help ensure that RAM was cleared during the boot up process. That is moot now because it no longer seems to help. Now every time after I boot, which has to be in safe mode, Activity Monitor shows that 5.3 GB of memory is already wired.
  4. macrumors 68020

    Sep 6, 2002
    I don't get why you have to boot to safe mode. What happens when you boot normally?
  5. thread starter macrumors newbie

    Jul 3, 2013
    If I try to boot normally, the Mac just hangs after the Apple logo goes away, and the gray screen fills up with strange patterns. I have to just turn it off at that point.
  6. macrumors 68030


    Nov 23, 2011
    Hi Mac09,

    Generally if you've had issues with RAM usage, resetting the PRAM & SMC can occasionally aid how OS X addresses RAM. May I ask if you've tried that?
  7. macrumors 68020

    Sep 6, 2002
    That sounds like more than a RAM use problem. It could be hardware. In any case, I'd let Apple look at it if you're near a store.
  8. macrumors 6502a

    Nov 13, 2008
    Actually some caches are good for the system to continue to perform optimally and cleaning them may cause more unwanted recourse then a necessary solution.

    I would try removing a few ram modules and operate on the bare minimum and see what happens there, reinstall the older modules and try again.

    if nothing else, do a clean install and reinstall your applications.
  9. thread starter macrumors newbie

    Jul 3, 2013
    Thanks for everyone's input.
    This happened at a bad time for me schedule wise, so it's going to be a little while before I can take my next steps. I will update this thread once I've gotten my Mac back to normal, and share whatever info that might prove useful to someone else with this predicament.
  10. macrumors P6


    Jan 24, 2010
    Something wrong with that kext would seem to indicate a strange software bug or a hardware problem with the GPU. As there are few, if any, reports of similar problems you may have a hardware problem.
  11. thread starter macrumors newbie

    Jul 3, 2013

    Yes, it seems to be a hardware problem -- bad video card.

    I did try removing the 2 third party RAM modules, but had the same problem.
    Also tried running the Apple Hardware Test (boot holding down the D key), which did not work.
    Then took the iMac into the Apple Store. This is the diagnosis:
    Steps to Reproduce: Booted to a known good OS and the screen got graphic distortion when it tried to load the graphical interface
    Proposed Resolution: Replace the video card

    One item of interest is that apparently the Apple Hardware Test is no longer supported -- that's why it didn't work for me.
  12. macrumors 65816


    Sep 30, 2009
    Surprised no one mentioned the free and awesome memtest utility.

    It sounds like you're all set now anyways.

Share This Page