Flashed 4870 Overheating, shutting off, MP 2010

Discussion in 'Mac Pro' started by slughead, Feb 4, 2012.

  1. slughead, Feb 4, 2012
    Last edited: Feb 4, 2012

    slughead macrumors 68040


    Apr 28, 2004
    Not sure if it's a fan failure or what. I bought this 4870 a while back pre-flashed. It worked great in my 1,1 MP and I boxed it after I got a 6870. The 4870 has been boxed for like 6 months. I got this MP 2010 Hexcore a week or two ago and just installed the 4870 to run a 3rd monitor (long story).

    The card showed the desktop background, external PSU running great, everything is happy. I watched TV on another video card for like an hour, and went back to play with the 4870 (working fine this whole time). I moved iTunes over to the 4870 monitor and re-sized the window... As I re-sized it, I heard noises like vibrating sounds coming from the case (presumably the card)!! I stopped moving the mouse, the noise stopped, I moved it again, the noise returned. Seriously the weirdest thing ever. About 10 seconds into this weirdness, the screen goes black and says "resolution outside of scan area" or something--basically the thing went kaput.

    I restarted and the screen turned on, then after booting and showing the desktop background, it overheated again.

    I popped open the case at that point and the card was really hot to the touch! I'm not sure but either the fan has stopped or there's a short somewhere that must have happened while the card was in storage.

    Is there some firmware issue with the new mac that causes the fan not to work? Does it change anything that I'm using SMC fan control (default settings)?

    Edit: The fan IS spinning, but not nearly as fast as the 5870 is... I wonder if I broke the fan in storage.

    Edit 2: I noticed the video doesn't come up until login.. that normal?
  2. Inconsequential macrumors 68000

    Sep 12, 2007
    The SMC does NOT control the GPU fan speed.

    So if it's not spinning up then the flashed BIOS has it's fan speed settings wrong.

    Reflash it with more suitable fan speeds...
  3. Neodym macrumors 68000


    Jul 5, 2002
    May not help in your specific situation, but a warning in general:

    The weak point of a 4870 are the voltage converters (lots of reports on the net). When you resize a window, the card needs to do more calculations and thus needs more power, which can lead to the converters making buzzing or chirping noises under certain circumstances.

    If you should come to a point where the video suddenly shuts off with a loud clack, power down the computer immediately and take out that card. I did not do it as the video signal came back after a while (think I rebooted). Short time later the converters died and they took the connected monitor with them in the process (voltage peaks on the DVI port I assume).

    Since that event I am wary towards aging 4870's.
  4. gpzjock macrumors 6502a

    May 4, 2009
    How are you powering both cards?

    If I understand you correctly there are 2 high power consumption GFX cards in your 2010 Mac Pro. Assuming they both need 2 power cables to get the required juice are you splitting the power from the 2 connectors on the mobo?
    I would not risk using both cards, an alternative for a 3rd monitor would be a GT120 which needs no extra power cable.

  5. slughead thread starter macrumors 68040


    Apr 28, 2004
    The 4870 is powered off a 2nd PSU outside the case.

    The heatsync on the card is VERY hot after only a few seconds of being on, even with no video displayed.
  6. gpzjock macrumors 6502a

    May 4, 2009
    Good to hear. Still think a GT120 is a better solution.

    So it is not insufficient power, good.
    Still think a GT120 makes more sense especially as a damaged 4870 could potentially damage the rest of your MP. Thinking of fitting a Haylon Dispenser just in case? :D

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