PS Fan won't go down to default 600rpm

Discussion in 'Mac Pro' started by flextone79, Aug 15, 2016.

  1. flextone79 macrumors newbie

    Joined:
    Aug 15, 2016
    #1
    Hi, long time lurker first time poster :)

    So I bought a 5,1 Hex core cMP and I'm mostly loving every minute of it. After years of using an iMac and Macbook Pros it's great to be back on the desktop. The only thing that is slightly bothering me are noise levels. It's not that loud, but l am very sensitive to such things and my apartment is extremely quiet.

    When getting the mac the fans were idling at around:

    PCI 1150
    Exhaust 600
    Intake 600
    PS 750
    Booster 800

    I've installed Macs Fan Control, dropped the PCI fan speed from +-1200 to 800 (sensor based, PCI ambience, 36-60. but why was it so off in the first place?), but actually that one wasn't so loud anyway.
    The fan which annoys me most is the PS fan. I'm seeing it's supposed to idle at 600 but mine won't go below 749rpm although the system is cool. This may not seem like much to most, but when I drop it to 600 with Macs Fan Control the difference in volume is substantial.

    How should I set up Macs Fan Control so that the PS fan slows down to 600 but still keeps the machine cool when things get more intense?

    Why is the PCI fan idling at 1000+ and PS at 750 in the first place? SMC reset didn't help. I did a fresh install of El Capitan. Rest of the system: 1TB HDD, 256GB pcie "blade" SSD, non-EFI GTX 670 on slot 1.


    Cheers,
    R
     
  2. xactoman macrumors member

    Joined:
    Jul 9, 2015
    #2
    I would open the machine up, remove the optical drive bay and blow a ton of compressed air in the power supply. There may be a dust of dust in the machine from over the years. That could lead to increased temps and the machine trying to cool it down.

    possible the PS is under load for some reason. The 670 have enough power?
     
  3. ScottishCaptain macrumors 6502a

    Joined:
    Oct 4, 2008
    #3
    Try loading the system down with something like an OpenGL benchmark or the iTunes visualizer.

    If your fans rise to an abnormally high level, let them do that... Afterwards, they should settle down to a quieter level.

    Assuming you see this behaviour, it's caused by a buggy SMC implementation. Apple doesn't want to fix it. The only solution is to load down the system until the fans rev high enough that the SMC reconsiders the fan speeds, at which point they'll drop to the level they should be at (until you do a cold boot).

    -SC
     
  4. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #4
    It's a known software bug, as the others suggest, stress your GPU for just few seconds can fix it.

    Or you can use MacsFanControl to setup your own Fan profile for both PCIe and PS fan, that can slo fix the issue (in a more automatic way).
     
  5. flextone79 thread starter macrumors newbie

    Joined:
    Aug 15, 2016
    #5
    Thanks.

    I've read about the OpenGL trick but it seems like too much hassle on every cold boot. I'm using MacsFanControl with the following settings for the PCI and PS fans:

    PCI - sensor based, PCI ambience, 33-60 degrees
    PS - sensor based, AC/DC supply 2 33-60 degrees

    This seems to give me the 800,600,600,600,850. CPU doesn't want to go down to 800 as well but with these settings together with SSD drives the system is rather quiet. Let's see how it handles a heavier work load.

    I am definitely going to open it up to clean ASAP. How can I check whether the 670 is getting enough power?
     
  6. h9826790, Aug 16, 2016
    Last edited: Aug 16, 2016

    h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #6
    CPU booster fan should never go below 800, that's normal.

    Update 1: Misread your post, yes, it should go down to 800, but not stay at 850.
     
  7. Synchro3 macrumors 65816

    Synchro3

    Joined:
    Jan 12, 2014
    #7
    Start CUDA-Z as startup item in the control panel.
     
  8. flextone79 thread starter macrumors newbie

    Joined:
    Aug 15, 2016
    #8
    I'm currently using the native OSX graphics drive. Would I be well advided to switch to NVIDIA web drivers? I'd hate to run into problems once I update the OS.
     
  9. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #9
    You may upload this screen capture. And check if we can find out why the CPU fan stay at 850RPM. (P.S. I manually setup the CPU fan profile, that's why it stay at 900, and intake stay at 700. I do that to lower the NB temperature for 5C during idle.)

    Screen Shot 2016-08-16 at 21.45.20.jpg
     
  10. Synchro3 macrumors 65816

    Synchro3

    Joined:
    Jan 12, 2014
    #10
    You don't need the web drivers for the GTX 670. Only install CUDA driver and CUDA-Z as Startup item.
     
  11. flextone79, Aug 26, 2016
    Last edited: Aug 26, 2016

    flextone79 thread starter macrumors newbie

    Joined:
    Aug 15, 2016
    #11
    Thanks, here's how mine looks like. Usually the PS stays at 600, today is kind of warm and it's misbehaving as you can see. PCIE and PS are both controlled by the sensors on a 34-60 slope.

    The IOH temperatures are substantially higher than yours. Not sure what that means. BTW it's a 2010 hex core 5,1 machine, and if I search specifically for this model, I see that the BOOSTA should actually be at 856 on these machines.

    What I've noticed is that, even if I turn off Macsfancontrol, the PS and PCIE fans don't rev up until the next cold boot.

    [​IMG]

    Do I need CUDA if I don't do any hardcore graphic work? Just the occasional photo editing on Photoshop and Lightroom.
     
  12. orph macrumors 6502a

    Joined:
    Dec 12, 2005
    Location:
    UK
    #12
    your gtx 670 has the power it needs or you'd not have anything on your screen, if where you live it is hotter than where h9826790 lives then your fans will have to spin faster, your fan speeds are not that high and there keeping your temps in check so :E your not going to gain much from 50rpms less on the fan.
    i live in wales, tends to be cool (we are lucky to get 16c most the time) but today i can see some sun (22c ish) and my fans are about the same speed as yours.

    if your used to imacs or laptops then more fan noise is one of the things that happen.
    there are a few things you can do tho. placement of your computer can change how much you hear the fans, i have a wall to the left of my computer (i sit on the right of it) that reflects a lot of sound back towards me when i had it set up in a more open space i heard less noise.
    Screen Shot 2016-08-26 at 3.30.58 pm.png
    edit ps thats just with firefox open with 50ish tabs open i gess
     
  13. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #13
    OK, that's absolutely normal, the exhaust fan is the ultimate control of the intake and booster fan. You can try to hard tune the exhaust fan to 700, then you can expect the see the intake also go up to 700, and booster go up to around 1000.

    The booster fan cannot go lower than ~1.42x of the exhaust fan speed. Since your exhaust is 600 now, so, 1.42x 600 ~ 850.

    The native fan speed vary from time to time, an OS upgrade may change the default fan speed. Some time ago, the default exhaust fan speed is 100RPM lower than the intake, that's 500RPM, so, the booster fan can stay at the min 800RPM, because it's higher than 1.42 x 500.

    And now, if the default is 600. I think 850RPM is the lowest you can get for the booster. Don't worry about that, you Mac is absolutely normal.

    About the NB temperature, the chip is rated up to something like 105C. So, your temp is actually good. I just personally don't like that. Therefore increase the idle fan RPM a bit to cool down the NB a bit more. It's just a personal preference.
     
  14. orph macrumors 6502a

    Joined:
    Dec 12, 2005
    Location:
    UK
    #14
    i kind of like the deep sound of the macpro fans, it's the sound of my GPU fans that tend to bug me.
    There much more high pitch and keep changing rpm by small amounts
     
  15. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #15
    Which GPU? When I 1st upgraded to 7950, it's the thing that annoy me so much. It's fan profile is very sensitive to loading. Just scrolling in Safari already keep the fan speed keep changing. At the end, I also custom made a fan profile for the GPU to fix it.
     
  16. orph macrumors 6502a

    Joined:
    Dec 12, 2005
    Location:
    UK
    #16
    iv got a evga 660 with twin fans, they dont change speed to often relay it's just that there higher pitched so i notice it more but only relay when playing games.
    im mostly used to it now
     
  17. flextone79 thread starter macrumors newbie

    Joined:
    Aug 15, 2016
    #17
    The general hum of the fans is quite lovely actually. The fan I find annoying is the PS fan. The moment it goes beyond 600 it sounds like there's a bumblebee in the room. Still need to do a clean up with compressed air. I guess my apartment is just too quiet for me. I live in Berlin which is very cold, therefore double windows which are always shut, and massive walls.

    Thanks for all the help guys, I'll shut up and start enjoying my mac now :)
     
  18. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #18
    That may have nothing to do with the fan, but the noise coming from other PSU electronics. From memory, another member report that quite a long time ago. At the end, he fixed it by installing a UPS. May be it's something to do with the power supply (I mean the power from the wall socket).

    That happen when PSU fan go above 600RPM may be a coincident. e.g. when PSU loading increase, some electronics start making noise, and then because loading increase, PSU temp also increase, eventually PSU fan RPM go above 600.

    AFAIK, that sound might be quite directional as well. e.g. you move your head few inches, then the noise disappear / or reduce a lot.

    An easy way to confirm if that's PSU fan related is keep the Mac at idle, but use MacsFanControl to manually increase the fan speed. If the noise start again, then it's the fan, or at least fan related. But if not, then it's PSU loading related, not the fan.
     

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