What is the 2010 PCI bay fan spec?

Discussion in 'Mac Pro' started by DanielCoffey, Oct 30, 2013.

  1. DanielCoffey macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #1
    Can anyone direct me to the technical information about the exact fan used in the 5,1 expansion bay? Specifically the size, amount of air moved, noise and max rpms?

    The reason I am asking is that I am having issues with removing the heat from my 7950 and want to look at ways of improving the cooling in that bay.

    I am aware that all the Apple fans are proprietary and use the 4th pin as a speed adjuster by varying the voltage. If you put a standard PWM fan in place of any of the Apple fans it will just run at 100% but there are reports of PWM fans being quieter at 100% than the official fans.

    My GPU is a flashed Sapphire 7950 Flex OC with Boost and it dumps the majority of its heat into the PCI bay and relies on the case fans to vent that heat. The PCI bay is correctly detecting all the heat and ramping up to get rid of it and the noise is intrusive.

    It isn't the GPU fans making the noise because GPU-Z reports 74C and 62% on the card. If I set the GPU fans manually to 62% they are not really audible and certainly not over the PCI bay fan.

    I would also like to know if the Apple fan holder can be disassembled easily to get at the fan. I know how to get the holder out of the case for cleaning but can't work out how it is all held together.

    Thanks in advance,

    Daniel.
     
  2. DanielCoffey thread starter macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #2
    If I wanted to temporarily set my expansion bay fan to a higher than typical speed to test the noise it produces at a given speed, how would you recommend I do it? I would prefer to just be able to raise the speed of that fan while the rest of the machine is idle to isolate the noise.

    When running Heaven, iStat reports the expansion bay fan steady at 1700rpm but in Skyrim under Win7-64 I think it is getting even higher (and therefore louder) so I am trying to work out if I have a defective fan while I am still under Applecare.
     
  3. Macsonic macrumors 65816

    Macsonic

    Joined:
    Sep 6, 2009
    Location:
    Earth
    #3
    Hi Daniel Though not sure if this is the solution. Have you tried removing some of your PCie card and check if the PCie fan speed decreases? Or if you have a different video card to test and check if the source of heat is coming from the video card.
     
  4. DanielCoffey thread starter macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #4
    Yes I do have my original Apple 5870 but the heat source is the 7950 when under load.

    iStat shows the PCI bay fan responding correctly to the heat when benchmarks are run. It ramps up smoothly and falls correctly when the benchmark is over.

    I have isolated it to the PCI bay fan because I have used the TriXX Sapphire utility to manually set the GPU fan to the same % as when it was running the benchmarks and the noise I hear is not the GPU fan.

    I notice it on the Windows side with games such as Skyrim with an ENB or Bioshock Infinite as well as Heaven/Valley. When the card is at 100% load it produces enough heat that the PCI fan needs to spin fast enough to be clearly audible.
     

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