Possible GPU Fan issue (?) with 2009 Mac Pro Dual 2.26

Discussion in 'Mac Pro' started by Seems like Trav, Aug 1, 2013.

  1. Seems like Trav macrumors newbie

    Sep 21, 2009
    I posted this on Apple Discussions but trying here hoping to get a reply.

    I've been using this machine since early 2009 and this "issue" has just seemed to appear suddenly about 2 weeks ago or so. The graphics card is the ATI Radeon HD 4870 512 MB.

    What's happening is, when putting on a game (in Mtn Lion, Snow Leopard, or Vista) the fan will suddenly ramp up. Not gradually, but immediately. It's louder when there's actual gameplay and quieter during a menu for example but it's louder than normal either way (usually almost silent normally), but for example as more activity occurn onscreen it is immediately louder, but might slow down immediately when the action stops or the game ends. If something blows up (explosion) in the game you will hear the fans rev up loud for the second or 2 that it's on the screen, and then quiet down again, as one example.

    With normal use it is almost back to its quiet state but seemingly a tad more audible than I can remember it being, but not much. Mistat, and istat Pro show Boost A and B (I Don't know what those are) about 1800, give or take, during normal use (it's at about 1700-1900rpm and a little more audible than usual as I type this) and hits roughly 2200rpm or so during a game. The Expansion is usually at about 900trpm or a little over 1000 but i don't remember them before so don;t know if this is alarming or not. All Temp readings seem to be normal or average from what I've remebered or have looked up elsewhere. GPU-Z monitor in windows states the GPU temp at about 90C, give or take and that seems to be about normal according to what i can find on it.

    Hardware test turns up nothing and Applecare has (naturally) expired a while ago (without the option to renew). SMC was reset twice. Computer is cleaned out for dust inside every 6 mos. A replacement card seemes to be gone from the store and the price for the other compatable ATI 5870 is still (a ridiculous) 400+, so that's a last resort for now. I just wanted to try to find out if this was a sign of a current or looming problem, or just possibly normal effects of "aging" equipment and thus nothing to be concerned about considering the circumstances. Any input welcomed, of course.

    Thank you.

  2. ActionableMango macrumors G3


    Sep 21, 2010
    Your problem occurs in multiple operating systems, so sounds like a hardware issue.

    Fans seem to be good. You've cleaned out the dust. Perhaps the heatsink isn't seated well or didn't have the thermal paste applied well and it's finally showing problems. You could pull of the heatsink, clean it up, reapply fresh thermal paste, and reseat.

    No matter what I wouldn't buy an Apple 5870 at this point; they are too old and overpriced. If you do buy a new video card and want a supported solution, there are the new Mac Edition cards from Sapphire (AMD) and eVGA (Nvidia).

    Alternatively, if you don't mind an unofficial solution, there are a plethora of PC cards that work well in Mac Pro these days. I personally have a GTX 680 and it works quite well. OOTB it works after bootup (no bootscreens) and it is very easily flashed to get the bootscreens and make it 100%.
  3. Seems like Trav thread starter macrumors newbie

    Sep 21, 2009
    Okay, thanks. if it is indeed a heat sink issue, that;s not really something i think i would like to tackle myself. I might look into one of thise cards if things seem to get worse. What are the boostes and do those numbers (say 2700 rpm while in Photoshop for example) sound high?
  4. DanielCoffey macrumors 65816


    Nov 15, 2010
    Edinburgh, UK
    I can confirm that many brands of PC 7950 3Gb cards are relatively affordable, available and work out of the box too.

    I am currently using a Sapphire 7950 3Gb Flex OC with Boost (Manufacturer ref 11196-17-40G) which I have flashed using the guides at Netkas so I get the boot screens.

    With 10.8.4, no drivers or tweaks of any kind are necessary and it has mDP ports so my existing display goes right in.
  5. xcodeSyn macrumors 6502a

    Nov 25, 2012
    BoostA and B are the fan speeds from the heatsinks over the CPU A and B. My MP 4,1 has a default speed around 1100-1300, so your default at 1800 is a bit high unless you live in a tropical climate. Even though you clean out the inside on a regular basis, I am sure there are components that may need to be taken apart for cleaning over time, such as GPU, CPU heatsinks, or northbridge heatsink. If you don't want do it yourself, you could probably find a professional doing it, or get a new and more efficient GPU as others suggested.

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