Do fans ever speed up in new mac pro ?

Discussion in 'Mac Pro' started by phjo, Jan 30, 2008.

  1. phjo macrumors regular

    Joined:
    Jan 8, 2008
    #1
    Hi,

    When doing some extensing calculations, I've monitored the temperatures rising, according to istatpro to something like :

    about 50°C for the cpu(s) (which I am quite confortable with...)
    up to 75°C for the first two memory dimms (which is a bit too much for my taste, although about the same than barefeats findings...)

    I would except smc to speed up a bit the fans for cpu/memory and exhaust but I never did see them change...

    they keep running at 600rpm for cpu/memory, 700rpm exhaust...

    (I don't get btw the reason for the harddrive fan to run at 800rpm, the cpu/fan sound more important to me...)

    So what are the temperatures to be reached for smc to speed up the fans ?

    phjo

    P.S. : with smcfancontrol, and cpu/memory fan raised to 730rpm as minimal, cpu temp tops at 40-41°C, and memory at 63°C which I find ok, so it just out of curiosity that I ask this :

    Do you ever see/hear your fans go up when doing extensive calculations ?
     
  2. johny5 macrumors 6502a

    johny5

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    UK
  3. netnothing macrumors 68040

    netnothing

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    Mar 13, 2007
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    NH
    #4
    Best I've seen with my 2006 Mac Pro model is Apple increasing fan speeds enough to keep some memory dimms at around 80C and not getting higher than that.

    -Kevin
     
  4. aLoC macrumors 6502a

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    Nov 10, 2006
    #5
    They have only revved up once in the 4 weeks that I've had it - for about 30 seconds while playing Civilization IV.
     
  5. phjo thread starter macrumors regular

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    Jan 8, 2008
    #6
    I would guess it was the video card fan you heard then...

    (N.B. : a slight increase in fan speed is rather difficult to hear, but could be monitored with istat pro for example...)

    phjo
     
  6. phjo thread starter macrumors regular

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    Jan 8, 2008
    #7
    It sounds insane to wait for such temperature to be reached to change fan speeds...

    smcfancontrol it is I guess,

    phjo
     
  7. netnothing macrumors 68040

    netnothing

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    Location:
    NH
    #8
    Yeah...I really wish we didn't have to rely on using other software to adjust the fan speeds and minimums. I understand Apple wants to keep these machine quiet, but even increasing my fans to 710rpm, drops the temps.

    I had a question for you on this other thread:
    http://forums.macrumors.com/showthread.php?t=425529

    Do you run smcFanControl all the time? What levels do you run at?

    -Kevin
     
  8. Jonny427 macrumors regular

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    Oct 16, 2007
    Location:
    Orange County, CA
    #9
    I think the hard drive fans are smaller and thus have to spin faster, hence 800rpm.
     
  9. ceres macrumors regular

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    Nov 14, 2007
    Location:
    Dark Forests of Germania
    #10
    I did some tests running Nero H264 Encoder with 8 active encoding threads and monitored in Vista 64 with the latest Everest Monitor.
    As the guys stated above the fans didn´t rev up past Apple´s minimum settings. They didn´t have to. CPU Core Temps didn´t exceed 61 degrees celsius at 100 % load. HDD and GPU were really good and even the RAM stayed around 53 degrees celsius. If anything at all, minimum fan speed settings are set too high at idle. 400 RPM would seem sufficient for scenarios without load.

    ceres
     
  10. phjo thread starter macrumors regular

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    Jan 8, 2008
    #11
    The temperature on the ram chips is quite impressive (low). Are they only the two 1Gb stock ram ?

    (I didn't test the temperatures with the stock configuration, but I guess it is much easier to keep the dimms cool, with only one dimm on each riser and the stock ram being 1Gb sticks makes them run a bit cooler as well...)

    How long did your burn test run ? (a few minutes is not enough, it really has to run for at least 30 minutes or more to see the temps go up and stabilize...)

    I do agree in your case there was no reason to speed up the fans, but I do see quite different figures here, with memory going easily higher than 70°C without some more rpm, manually added, for the cpu/mem...

    phjo
     
  11. phjo thread starter macrumors regular

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    Jan 8, 2008
    #12
    I finally did acknowledge some fans speed adjustment !

    Setting back fan speed to default minimum, I could see some tiny adjustments of the fans speeds : cpu/mem fan speed gets bumped a few dozen of rpms, then back to default, then up again (top speed I could monitor : about 550 instead of the 500 default...)

    It makes me feel that smc actually does something (which I really doubted !) although I'd rather have more conservative figures...

    phjo
     
  12. ceres macrumors regular

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    Nov 14, 2007
    Location:
    Dark Forests of Germania
    #13

    Hi,
    I had 2 dvd9 images queued up and the entire test ran about 140 mins.
    Yes, I have the standard 2*1gb installed right now bc there are no major manufacturers out there shipping 800mhz modules (afaik).
     
  13. netnothing macrumors 68040

    netnothing

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    #14
    Yeah...I had the same question as phjo....so with the single DIMMS being separated between the risers...that's what is keeping things cool.

    If/when you get more memory.....run the same test and report back. It would be interesting to see the results.

    -Kevin
     
  14. netnothing macrumors 68040

    netnothing

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    #15
    Hey phjo.....the ONLY time I have ever had Apple kick up the fans, like I said in my previous post, was after I put in the 8GB I would kick up the heat in the room - ambient to 80F....and I'd be running Rember to test all the ram. Granted, Rember only uses 1 CPU at a time.....but those RAM DIMMS got to about 175F before Apple kick up the fans...just enough to keep them there.

    I'm guessing that Apple coded it so that if 'everything' was starting to get hot....like you were doing a render and all CPUs were cranked, and the memory was cranked....then they'd start to ramp up the fans.

    I wish Apple would add a preference pane, even if it's tied to the dev tools being installed, to allow some control to the fans and levels in which they speed up.

    -Kevin
     

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