Strange Freezing on iMac i7 8gb

Discussion in 'iMac' started by tarakul, Mar 4, 2010.

  1. tarakul macrumors newbie

    Joined:
    Dec 16, 2009
    #1
    Hi Everyone

    Got a strange problem, Snow Leopard freezes. It is a strange freezing that occurs at any time when I am doing anything - the only constant seems to be when I am heavily multi tasking.

    When it occurs I can move the mouse but the UI does not respond to any clicks, be it to click on a hyperlink on a web page on the frozen screen, or to minimise/close a window that happened to be open when it froze.

    The strange thing is the dock appears from hiding and the icons magnify when I hover over them but again no response when I click, the mac menu bar along the top is also unresponsive.

    The only thing to do is press and hold power and restart.

    It has happened two three times each time I use the machine since I got it.
     
  2. spinnerlys Guest

    spinnerlys

    Joined:
    Sep 7, 2008
    Location:
    forlod bygningen
    #2
    Have you tried repairing the permissions via Disk Utility?

    Have you taken a look at Activity Monitor or iStat Menus and seen what process might hog up the CPU?
     
  3. tarakul thread starter macrumors newbie

    Joined:
    Dec 16, 2009
    #3
    I have downloaded the latest updates. I have repaired the disk and permissions.

    When it crashes I can not open activity monitor or iStat - the only thing that responds is the dock icon magnification - other than that no single element on screen responds to clicks.
     
  4. Ecoh macrumors 6502a

    Ecoh

    Joined:
    Oct 30, 2009
    Location:
    USA
    #4
    I have the same symptoms on my i7, happened 3-4 times a day. Called Applecare and they told me to do PRAM reset. The problem went away for a month and then came back. Called Applecare again and was told to bring it in for repair , the problem could be the graphics card
     
  5. ekol macrumors newbie

    Joined:
    Jun 17, 2010
    #5
    Hi, I have the same problem today... Music still playing but everthing is completly frozen...

    Any idea or just a hardware problem... i have applecare until 2012, I can wait a little more...
     
  6. DoFoT9 macrumors P6

    DoFoT9

    Joined:
    Jun 11, 2007
    Location:
    Singapore
    #6
    hey guys - i have the SAME problem! i just upgraded my iMac from 4GB to 8GB (2x2 stock + 1x4). now the entire computer will freeze up whenever it wants to. i cannot use it as i fear i will loose work.

    i just upgraded to 10.6.4 hopefully that might fix it - did you guys ever find a fix?
     
  7. spinnerlys Guest

    spinnerlys

    Joined:
    Sep 7, 2008
    Location:
    forlod bygningen
    #7
    Have you checked if it is not the RAM by pulling the 4GB stick out again?
     
  8. teksmith macrumors newbie

    Joined:
    Aug 1, 2010
    #8
    Mac Snow Leopard 27" Freeze after 8gb Upgrade

    I am seeing the same thing. I added four more GB for a total of 8GB and now my Mac freezes randomly. It was rock solid. I pulled out the 4GB and no more freezing. I wonder if there is a 64 bit addressing bug???
     
  9. skcrane macrumors member

    Joined:
    Mar 24, 2009
    Location:
    dayton, oh
    #9
    I have been doing some research and it says with the quad core i5, i7 you must run with both ram modules full, or one ram module full.
     
  10. DoFoT9 macrumors P6

    DoFoT9

    Joined:
    Jun 11, 2007
    Location:
    Singapore
    #10
    certainly did

    you know, i followed this up, and APPARENTLY you need to run the "odd" stick in slot 1. i sure hope that this work around doesnt work, because i purchased 2x4GB sticks and i still have my 1x4GB stick lol.
     
  11. teksmith macrumors newbie

    Joined:
    Aug 1, 2010
    #11
    No Odd Sticks

    I have 4x2GB so no odd sticks. I did a pram reset mentioned above and I have not frozen since but I also haven't really done a lot of multitasking either. If I have not had a freeze by next week, I will claim victory.
     
  12. DoFoT9 macrumors P6

    DoFoT9

    Joined:
    Jun 11, 2007
    Location:
    Singapore
    #12
    good information, thanks. i never did a PRAM reset from what i can remember. the freezes happened whenever i addressed more then the original 4GB RAM, i still have the stick lying around but have ordered 2x4GB sticks anyway :D
     
  13. teksmith macrumors newbie

    Joined:
    Aug 1, 2010
    #13
    Just froze up again. I hope I don't have to go with 4GB to ensure reliability. I will be so disappointed with my mac. This is my first one and I like it, but this sucks. My last few PC's were actually pretty reliable. I will let you know what I find out.
     
  14. aliensporebomb macrumors 68000

    aliensporebomb

    Joined:
    Jun 19, 2005
    Location:
    Minneapolis, MN, USA, Urth
    #14
    Guys

    Bad ram stick?

    Here's how mine is set up:

    Original 2 GB ram sticks in slot A and B closest to the front of the machine (screen side).

    I have installed two 4-GB chips on slots A and B of the slot closest to the back of the machine.

    Remember ram MUST be installed in matched pairs for it to work so nothing like this:

    2 GB + 2 GB
    4 GB

    Or:

    2 GB + 4 GB
    4 GB + 4 GB

    It would have to be matched sets of whatever it is you're running:

    i.e.

    2 GB + 2 GB
    4 GB + 4 GB

    And you can't run just one chip in the second set of slots and leave one empty and have it work.
     
  15. DoFoT9 macrumors P6

    DoFoT9

    Joined:
    Jun 11, 2007
    Location:
    Singapore
    #15
    aliens is right - i had a freeze this morning using 3x4GBs + 1x2GB sticks. bit annoying that you cant do that, what is the justifications behind such a thing?
     
  16. aliensporebomb macrumors 68000

    aliensporebomb

    Joined:
    Jun 19, 2005
    Location:
    Minneapolis, MN, USA, Urth
    #16
    Ah

    Multichannel RAM basically. The best way I can explain it is that each set works together as a single unit in some respects.
     
  17. DoFoT9 macrumors P6

    DoFoT9

    Joined:
    Jun 11, 2007
    Location:
    Singapore
    #17
    which doesnt really make much sense - because on a BIOS based system it should work, right?

    so therefore its the way that OSX (EFI) handles it - which is a bit odd because all it has to do is give memory associations, i cant imagine it being that hard :p
     
  18. bolen macrumors 6502

    bolen

    Joined:
    Jul 22, 2008
    Location:
    Sweden
    #18
    I believe it's the same for BIOS based systems. I've experienced similar results on a friends i7 PC that was solved by moving around the RAM.
     
  19. DoFoT9 macrumors P6

    DoFoT9

    Joined:
    Jun 11, 2007
    Location:
    Singapore
    #19
    odd, i recall mixing and matching RAM back about 10 years ago in my PCs. :\
     
  20. aliensporebomb macrumors 68000

    aliensporebomb

    Joined:
    Jun 19, 2005
    Location:
    Minneapolis, MN, USA, Urth
    #20
    As an aside...

    This is going to sound really weird but just moving ram sticks around can have a noticeble effect on performance.

    My G5 tower has 8 one gigabyte PC3200 sticks in it.

    In ONE particular order I can get the machine to geekbench the fastest a G5 2.5 can which is 2312 - as far as the G5 2.7 machines.

    In no other order can it get close to that.

    So I wonder if sometimes positioning is everything..
     

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