4850 Owners, Want to see if a possible short-term fix will work

Discussion in 'iMac' started by VulnoX, Apr 28, 2009.

  1. VulnoX macrumors member

    Joined:
    Apr 23, 2009
    #1
    So I got my iMac today, played with it all day, and it wasn't until I played WoW for about a half hour with all settings at full tilt on WiFi that it locked up.

    The thing was hot as hell, and the fans weren't even trying. So taking a lesson from other users on the Apple Support Boards, I installed SMCFanControl

    I set most of the settings to about the mid-range, its slightly louder, but nothing I really notice. I actually feel air coming from the vents though.

    Been going for about an hour with WiFi on without a lockup.

    Now, you can hear the fans quite a bit more at this level. What I am looking for is if some people want to install this, try these settings and see if it locks up, if not, then lower the fans a bit. See if we can't get them low enough to where they aren't noticeable when using the iMac, but are actually cooling better than whatever Apple set them to do. I need to get to bed soon so WoW is going off in a bit, but if you try this, let me know your results!
     
  2. Headliner macrumors newbie

    Joined:
    Nov 29, 2007
    #2
    This has been tested before. Some have had said it helps but I didnt notice any difference.

    Temporary fix for now is to use Ethernet to connect to network/internet and turn airport off. Unfortunately for me that's not an option. According to Apple a fix is in the works so shouldn't be too long now. :D
     
  3. Theraker007 macrumors regular

    Joined:
    Mar 3, 2009
    #3
    no lock up for 24 hrs and counting. set min all the way to the left and max at 70 degrees C
     
  4. DELTAsnake macrumors 6502

    DELTAsnake

    Joined:
    Jul 18, 2008
    Location:
    Australia
    #4
    I don't think it's heat related because people are reporting freezing using nothing but Firefox.

    My fans are normally low, the one time the iMac got really hot was on a hot day and the fans did spin up.
     
  5. MacAndy74 macrumors 65816

    Joined:
    Mar 19, 2009
    Location:
    Australia
    #5
    Have Apple actually posted an article about this problem?
    Just wondering. :eek:
     
  6. Headliner macrumors newbie

    Joined:
    Nov 29, 2007
    #6
    No, but the tech support have told me and several other people the same thing: Fix may come bundled within 10.5.7 update or released before separately. (Whether you can believe that or not is another issue. :rolleyes: No word on what the problem actually is yet let alone trying to fix it. Not that I don't trust Apple's capable engineers. lol)

    I wouldn't really expect them to post an article on it though. They only want to inform the people who have the problem otherwise they'd be making the problem itself very public which wouldn't be very good publicity. After all, those who aren't tech savvy could assume its the entire iMac line up affected.
     
  7. davemulheran macrumors regular

    Joined:
    Mar 6, 2009
    Location:
    UK - London/Kent
    #7
    Deffo not heat related.
    My two freeze within 30 seconds to 1 minute of being left idle, after being booted up from stone cold first thing in the morning
     
  8. WizardHunt macrumors 68000

    WizardHunt

    Joined:
    May 11, 2007
    Location:
    Las Vegas, Nevada USA
    #8
    interesting I thought it might be a heat issue as well. I installed istat to check mine and it was like 72 C for my GPU temp. But haven't freezed since i installed the istat so don't know what temp it was when it froze. However i also had it freeze on email and in iphoto and not doing much (not hot at all) so that blows that theory I guess. :p
     
  9. Shivetya macrumors 65816

    Joined:
    Jan 16, 2008
  10. GamaFu macrumors regular

    Joined:
    Apr 12, 2007
    #10
    I seriously doubt overheating is the problem here.
    My iMac freezes when I watch videos on YouTube or Hulu the temperature is only 50 something Celsius.
     
  11. GonzoRob macrumors 6502

    GonzoRob

    Joined:
    Sep 1, 2004
    #11
    agreed. same here....
     
  12. dolmen69 macrumors newbie

    Joined:
    Apr 22, 2009
    #12
    Well I think it's an heat issue. The fact that it can freeze even after one minute after poweron during nothing does not mean it is not an heat issue.
    My understanding is that there is something related to ATI4850 affected by heating problem. And this threshold is not fixed for every iMac. With mine, simply using WiFi off solve the issue. Other ones simply installing fan control.
    Someone else has to do both things to solve issue.
    Other ones Wifi off reduce the problem but not fix it. Like for me installing fan control reduced the issue but didn't fix it.
     
  13. VulnoX thread starter macrumors member

    Joined:
    Apr 23, 2009
    #13
    I thought it was heat because my two day old 4850 DOES NOT freeze when doing regular activities on the iMac. No problem with iTunes (Full Screen Visualizer or not) for over an hour, no problems when installing programs, basically no problems at all except when I play World of Warcraft on Wifi. After about 30-60 Mins, lockup.

    My theory was that maybe it IS a heat issue, but its not the videocard overheating which people focus on a lot. Maybe the Airport card is close to the video card, and its the extra heat (even if its only 60-70 degrees on the videocard) that is causing the issue.

    Even if your computer has been on for 5 minutes, that video card gets up to over 100 degrees F. That is enough radiating heat to warm up the Airport more than it may have been designed for.

    The Nvidia's may not radiate as much so most GT130's escape this issue, and it would also explain why the GT130's that have the problem are only after playing a video game like WoW which would then push them up to ATI levels.
     
  14. spatterfree macrumors member

    Joined:
    Apr 8, 2009
    Location:
    South Dakota
    #14
    uptime on 4 days, GPU on 135 degree, working PERFECT!! no complaints here,
    i don't suspend, so it's been running for 4 days already,
     
  15. WizardHunt macrumors 68000

    WizardHunt

    Joined:
    May 11, 2007
    Location:
    Las Vegas, Nevada USA
    #15
    Just curious When you got your iMac, did you transfer any of your files? Or did you do a fresh install? Also what do you do with your iMac? like surfing only, going to youtube, or playing movies, or games or what? Do you have DivX installed?
     
  16. VulnoX thread starter macrumors member

    Joined:
    Apr 23, 2009
    #16
    I know you asked him, but I wanted to throw mine in too because I seem to be having some different freezing than you.

    No files transfered.
    I do surfing, movies/tv shows, and WoW at Ultra Settings. Also Photoshop work and music (which I am doing now).

    The iMac ONLY freezes when I do WoW on WiFi, otherwise, have not had a single freeze, including letting it run for a couple hours on FS Visualizer in iTunes.

    Which is where I get my question for you.

    Which Visualizer do you use, the default one? Do you change any settings for the visualizer to get it to freeze? I can't get mine to lockup on that and I am wondering if there is something I am overlooking.
     
  17. WizardHunt macrumors 68000

    WizardHunt

    Joined:
    May 11, 2007
    Location:
    Las Vegas, Nevada USA
    #17
    I use the Default Visualizer and make no changes to it. It just locks up sometimes on the first song, or 3rd song or 10th song or 2 hours later just pure random. I do display it full screen.
     
  18. Theraker007 macrumors regular

    Joined:
    Mar 3, 2009
    #18
    2 days and running, no crashes since fan speeds up'ed
     
  19. Bad Paper macrumors 6502

    Joined:
    Apr 20, 2007
    Location:
    graphite clamshell
    #19
    huh. Mine has never crashed, and I have pummelled it with, for example, Fusion runnning SAS in an XP window in the background while I play World of Warcraft. Oh, and Mozy doing its backup thing.

    And of course Dead Space. ohhhh Dead Space, yum.

    It's not a stress issue. I suspect it's a bad-chip-manufacturing issue with the 4850s, and therefore completely random.
     
  20. VulnoX thread starter macrumors member

    Joined:
    Apr 23, 2009
    #20
    Ok, but are you actually using WiFi? If it were random and based on chips, I would think we would see it in the other systems that use the 4850.
     

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