PCI-E fans Rev viewing pictures

Discussion in 'Mac Pro' started by AkuskaUK, Sep 27, 2014.

  1. AkuskaUK macrumors 6502

    AkuskaUK

    Joined:
    Mar 18, 2011
    Location:
    Shanklin, Isle Of Wight
    #1
    Hi everyone, I seem to have a weird problem with my Mac Pro. When viewing images though quicklook (space bar) or in iPhoto and preview, my PCI-E fans decide to Rev to about 1800-2000rpm before settling down again about 2 mins later.

    Any help? Thanks in advance.
     
  2. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #2
    When you start to have this issue?

    Did you change any hardware? (especially the graphic card)
     
  3. AkuskaUK thread starter macrumors 6502

    AkuskaUK

    Joined:
    Mar 18, 2011
    Location:
    Shanklin, Isle Of Wight
    #3
    I replaced my 5770 with a MVC GTX770. I didn't think it would be an issue.
     
  4. Macsonic macrumors 65816

    Macsonic

    Joined:
    Sep 6, 2009
    Location:
    Earth
    #4
    I am using a modded MVC 770Gtx by EVGA and no problems on the PCIe fans running too high when I view images. Not using any third party fan control software. On turning on the computer, the PCIe fan goes at around 1250rpm, after awhile goes down to 1100rpm until it settles down to 799 to 801rpm. I also have a Nvidia EVGA 680gtx Mac Edition and the PCIe fan also behaves in the same manner as the flashed 770Gtx. I keep an extra Mac Edition GPU for backup, reference and comparison.
     
  5. AkuskaUK thread starter macrumors 6502

    AkuskaUK

    Joined:
    Mar 18, 2011
    Location:
    Shanklin, Isle Of Wight
    #5
    Mine does exactly that, but also revs when I view an image :s it is bizarre!
     
  6. ScottishCaptain macrumors 6502a

    Joined:
    Oct 4, 2008
    #6
    SMC firmware is defective.

    Apple knows about this, but they don't care. The only official GPUs the SMC actually supports are the ones that shipped with the Mac Pro. Flashed cards and even the 680 GTX (Mac Edition) can and often do cause whacky fan behaviour.

    This more or less has to do with how the fans are throttled based on the power the card is consuming. The formula they're using for this isn't optimal for cards with their own cooling fans, so the increased power load causes the fans to spin up to unnecessary speeds.

    Chances are good that if you "force" the issue by loading down the GPU (iTunes Visualizer, running a game, or an OpenGL benchmark, etc)- the fans will rev up, then start to settle down again. Once this happens, the fan speed should stay low until you power down the computer.

    -SC
     
  7. AkuskaUK thread starter macrumors 6502

    AkuskaUK

    Joined:
    Mar 18, 2011
    Location:
    Shanklin, Isle Of Wight
    #7
    Thank you. Doing what you said does make the fans speed up and then slow down. At least you knew what the problem is! Thank you. Ill just have to put up with it then, its an annoyance.
     

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