5,1 booster fan speeds

Discussion in 'Mac Pro' started by Morpheo, Sep 14, 2017.

  1. Morpheo macrumors 65816

    Morpheo

    Joined:
    Feb 26, 2014
    Location:
    Paris/Montreal
    #1
    Every once in a while it seems I'm getting a bit obsessed with my fan speeds...Just trying to make sure if they are normal or not, it probably goes back to the days when I first upgraded the CPUs on my MDD G4!! :)

    So, here we go, I noticed this morning that my booster fans always seem to be in the 1700 rpm range, more or less. That's when the computer is mostly idle (safari and mail are running). If I'm running, say, a heavy Pro Tools session (dozens of tracks, VI plugins, video, inserts, etc), they don't really go up either.

    What do you think?

    Everything is stock on this Mac Pro, from the original CPUs to the aging but still good enough 5770...

    Screen Shot 2017-09-14 at 9.53.36 AM.png
     
  2. Studio K macrumors 6502

    Studio K

    Joined:
    Feb 17, 2013
    Location:
    United States
    #2
    BOOST fans are running higher than normal, I believe. A Dual CPU system like yours should run BOOST fans several hundred RPMs slower at idle (like 1100 each).
    Not sure what to suggest, but I'll think about it and get back.
     
  3. owbp, Sep 14, 2017
    Last edited: Sep 14, 2017

    owbp macrumors 6502a

    owbp

    Joined:
    Jan 28, 2016
    Location:
    Belgrade, Serbia
    #3
    With those fan speeds and system ambient Northridge should be a lot cooler, so I would check plastic rivets on it's heatsink first (or it could be just dust buildup on heatsink).
    Also PCI-e slot 1 is to hot, maybe you should look into cleaning GPU. But that's not causing booster fans to ramp up.
     
  4. Studio K macrumors 6502

    Studio K

    Joined:
    Feb 17, 2013
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    United States
    #4
    The Northbridge temp is not alarmingly high at 74C. Machines with broken rivets tend to run over 100C.

    You can try the usual Apple fixes: reset the NVRAM (command-alt-P-R keys at startup) and the SMC reset (unplug machine, hold power button down).

    Then there is the option to remove heatsinks, reapply thermal compound to CPUs.
     
  5. h9826790 macrumors G5

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #5
    The root problem is not the boost fan, but exhaust fan. There is a specific ratio between exhaust and boost fan. I believe it's about 1.85 on the dual processor 5,1. Since your exhaust fan spin up to 934. It forced the intake also spin up to 934, and both boost fan spin up to 934 x 1.85 = ~1727 RPM

    So, obviously the fans are working properly, however, something cause the exhaust fan to spin up.

    Even I am with the single processor 4,1, the North bridge (NB) is a bit cooler, but should not be a huge difference than yours. I set my fan to match your boost and in/ext fan speed. Which cool down my NB to around 49C (25C lower than yours) even my system ambient is 1C above yours.

    It really suggest that your cMP's cooling system is not working properly. Since you didn't post the whole iStat image, so we can't see what's your CPU idle temperature. However, I can hardly imagine a idle CPU is warm enough to spin up the fans.

    Your NB heatsink is just 10C cooler than the NB. It means the heat actually able to transfer to the heatsink. The rivets most likely are fine at this moment. However, the NB heatsink is easily blocked by dust. So, you may have a good look of that. I also agree that 74C is not a problem at all, however, a warm NB may cause the fans to spin up.
    Screen Shot 2017-09-14 at 23.48.51.jpg
     
  6. Morpheo thread starter macrumors 65816

    Morpheo

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    Feb 26, 2014
    Location:
    Paris/Montreal
    #6
    hmm.. ok, I don't like that!... I'm going to open and see if I can brush off the dust.
    --- Post Merged, Sep 14, 2017 ---
    Here's a more complete reading from istat... taken a moment ago.

    Screen Shot 2017-09-14 at 1.07.00 PM.png
     
  7. owbp macrumors 6502a

    owbp

    Joined:
    Jan 28, 2016
    Location:
    Belgrade, Serbia
    #7
    Actually it all depends on position of heatsink when rivet breaks.
    My friend has 4,1 that works normal with one rivet broken. The temperatures are in high 70s range when idling and jump quite a bit, together with fan speeds, if doing his work (he's directing commercials etc).
    On the other hand, some Macs won't boot as soon as the rivet breaks.

    It should be examined, it's quite possible just some dust buildup.
     
  8. Studio K macrumors 6502

    Studio K

    Joined:
    Feb 17, 2013
    Location:
    United States
    #8
    I agree. It should be checked out. If the OP does resort to removing the CPU heatsinks for cleaning and/or thermal paste application, he would have the opportunity to look at the rivets on the NB heatsink.
     
  9. Morpheo thread starter macrumors 65816

    Morpheo

    Joined:
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    Paris/Montreal
    #9
    ...ok so threre was quite a bit of dust in there.

    Here's what I see after cleaning it up, boosters seems to be gravitating around 1200 now:



    Screen Shot 2017-09-14 at 2.15.42 PM.png
     
  10. Studio K macrumors 6502

    Studio K

    Joined:
    Feb 17, 2013
    Location:
    United States
    #10
    INTAKE & EXHAUST should normally be 600 RPMs, I think. That's the normal idle speed on single CPU model. Mabye nomral RPMs for those fans are a little more for dual CPU mac pro.

    Definitely take out the CPU/Ram tray and thoroughly blow the dust out. Blow a lot of air through the the heatsink fins.

    Don't know what else to say, I never had CPU, Intake, Exhaust anomalies before.
    --- Post Merged, Sep 14, 2017 ---
    What a BIG difference!! Those speeds look much more healthy.
    The 'normal' is, I believe, 600 RPM for Intake and Exhaust. And 1113 RPM for BOOST. You are much closer now.
     
  11. Morpheo thread starter macrumors 65816

    Morpheo

    Joined:
    Feb 26, 2014
    Location:
    Paris/Montreal
    #11
    Yeah I'm kinda suprised myself to see the difference. I just removed some dust (front fan and heatsink were the most affected...) :)

    There's still those I'm not sure what to make of it:

    Screen Shot 2017-09-14 at 2.26.17 PM.png

    Although I took apart my 1,1 several times, I never got that far (the CPUs...) with my 5,1. I don't want to damage anything as this is my primary computer...
     
  12. Derived macrumors 6502

    Derived

    Joined:
    Mar 1, 2015
    Location:
    Midwest
    #12
    I know my machine is pretty clean, although it close to a wall behind it, temps are pretty low, but my intake & exhaust fans stay at around 630-640 with quite a few apps running but not really doing much. If it was cooler in here or I had less apps running perhaps they'd dip back down. Boost fans are a tick over 1100, overall I really don't think you have anything to worry about.
     
  13. h9826790 macrumors G5

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #13
    As long as the exhaust fan is stay at ~600 (for both single and dual processor Mac Pro), it's good enough to consider the fans are run at true idle.

    Yes, dust makes huge difference. Even though your NB is still 75C, but that's with much lower fan speed. If you force the exhaust fan go back to 950RPM now (iStat has this function), you should see a much lower NB temperature. If not, that's definitely something wrong. Either you didn't clean the NB heatsink (they need a good blow from the back to clean it), or the rivet is not doing the job properly (the heatsink can be "sticked" to the NB by the thermal paste. Therefore, even the rivet is not applying good pressure. The heatsink can still do its job up to certain extend).
     
  14. Morpheo thread starter macrumors 65816

    Morpheo

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    Feb 26, 2014
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    Paris/Montreal
    #14

    I just found this thread: https://forums.macrumors.com/threads/mp-5-1-ioh-tdiode-running-hot-75c.1738371/

    Two posters suggest that 75ºC is normal for a dual CPU. One of them reports 75 and another 77.
     
  15. Sharky II macrumors 6502a

    Sharky II

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    Jan 6, 2004
    Location:
    United Kingdom
    #15
    75 degrees for NB is normal for dual cpu 4,1 and 5,1 systems
     
  16. lie2me macrumors member

    Joined:
    Apr 23, 2010
    Location:
    Somewhere
    #16

    After seeing your fan numbers, I really must have problems.
    My fan booster 1 fan speed is 0. My booster 2 fan speed is 5200. That is right, 5200.
    All others are below 1000 at about 22C ambient.

    Which CPU is adjacent the booster 2 fan on my 2009 Mac Pro?
    Since booster 1 fan never seems to run, that fan must be broken.

    IMG_0740.JPG





    My CPU temps seem to be OK since they are around 55C or less.

    IMG_0739.JPG
    --- Post Merged, Oct 27, 2017 ---
    Thanks for any replies in advance
    --- Post Merged, Oct 27, 2017 ---
    I look forward to any further posts.
     
  17. pdafan macrumors member

    Joined:
    Aug 2, 2011
    #17
     

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16 September 14, 2017