Display image starts breaking up

  • Posted: 28 June 2012 02:36 PM

    Ok, how do I explain this….

    After my MacPro has been running for a while or I’m using lots of applications at once, one or both of the displays will start acting wonky. The image will start breaking up into random patterns and becomes unusable.

    (I’ve attached one of the screenshots so you get an idea what it looks like)

    The only workaround fix to this I’ve found is to do a Shift-Command-4 screenshot and drag the crosshairs across the entire screen and that seems to reset it. Then I’ll reboot and it’s back to normal….until the next time it acts up again.

    Genius at Apple Store said to reinstall OS.
    Has anyone ever seen this or heard of this problem?


    (MacPro4,1 OS 10.6.8, dual Apple displays)

    Image Attachments

    Screen shot 2012-06-28 at 10.31.39 AM.jpg

    Click thumbnail to see full-size image

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    Posted: 28 June 2012 03:11 PM #1

    Huh… that looks a lot like video RAM (or the system entirely) is bogged down. When this happens, how much free RAM do you have? I realize that may be tough to tell, but I’m just curious what the “trigger” is to this. If it’s that you’re RAM bound, then that would make sense (and it might mean that waiting a little bit… 1-5 minutes… might solve the issue).


    -Dave Hamilton / The Mac Observer / Mac Geek Gab / Dave on Twitter
    When you find a big kettle of crazy, it’s best not to stir it.

  • Posted: 29 June 2012 01:06 PM #2

    It could be that. It seems to happen when I have lots going on at once or when it’s been a while since I’ve rebooted.
    I have 16GB of RAM though, isn’t that lots?
    The issue never resolves by itself. I end up doing the screenshot workaround just to keep clearing my screen until finally it’s happening too much and I have to reboot.
    I’ve never reinstalled the OS before so I’m a little nervous to do it but maybe it’s worth a try to see if it’ll clear it up.
    Anything else I could try?

  • Avatar

    Posted: 29 June 2012 02:56 PM #3

    It may actually be the video card going south. Possible heat issue?

  • Posted: 07 August 2012 12:04 AM #4


    I’ve seen this before.

    I used to see this happen on my mid-2007 2GHz, 2GB RAM Mac Mini!

    Wow.. it’s been a while since I’ve seen this behavior. It would happen briefly and very occasionally. Most of the time it would resolve itself. A few times, I, like you, had to do something to get it to fix itself. I don’t remember what I did.

    Here’s the thing. It did that when it was running Leopard. I then upgraded the Mac Mini to Snow Leopard and completely forgot all about it, as it didn’t do it again.

    The Mac Mini is now connected to the TV and is running Lion, like it was meant to. Has never run better.

    I had completely forgotten all about this. Huh…

    As was suggested, maybe reinstalling the operating system is the way to go.

    Hope you solve the problem.

    Let us know.