fan control for 980ti in Mac Pro 5,1

Discussion in 'Mac Pro' started by Somian, Apr 21, 2016.

  1. Somian macrumors member


    Feb 15, 2011
    Cupertino, CA

    I just updated my Mac Pro 5,1 to 10.11.4. and the latest nvidia driver release 346.03.06f01

    since, the fans of the 980ti are always spinning at max, sounding like a vacuum cleaner, even when the card is idling.

    It worked fine before the update. I could restore using time machine, but kinda want to use the latest OS (which requires the latest graphics driver).

    is there a way to control the video card fan speed in OS X?
  2. Mejenborg macrumors newbie


    Apr 22, 2016
    Aarhus, Denmark
    Which 980 Ti do you have?

    Myself I have the Asus 980 Ti Strix and the fans almost never spins up, only when expected during boot and with extreme graphics performance. I've been looking for a GPU fan control software for OS X, but unsuccessful. Though stumbled upon iStat Menus which gives me control of all the other fans in my Mac Pro.
  3. SteveJobzniak, Apr 22, 2016
    Last edited: Apr 24, 2016

    SteveJobzniak macrumors 6502


    Dec 24, 2015
    The graphics card itself shouldn't be boosting its fan speed. The card uses onboard logic and is not controlled by the computer. I.e. heat sensors/power draw on the card controls its fan speed. The best a Windows (not Mac) PC can do is that manufacturers sometimes give you special tools to overclock and to change the fan behavior. But since you are not running such a tool (none exist for OS X), it means the GPU fan is entirely controlled by the GPU itself, so there is no logical reason for why your card fan would speed up.

    I think your situation is that the PCI fan and PSU fan of the Mac Pro itself are the ones speeding up. That's what happened to me, because the Mac Pro is not made for the amount of power draw of a modern card, so the Mac's own fans speed up massively. I am still running perfectly with the solution I posted here:
  4. Somian thread starter macrumors member


    Feb 15, 2011
    Cupertino, CA

    Thaks for the replies.

    I have a ZOTAC GeForce GTX980Ti AMP Edition.

    It behaved just like you described all the time until i updated to 10.11.4.

    I restored to 10.11.3 now via a time-machine backup now, but i'd still like to fix that at some point.

    I know the video card should control its own fans, but something seems to be messed up here.

    What OS X version are you using? are you using 10.11.4 with the 346.03.06 driver?

    I'm using iStat menus, too, however, and even when I put the fans down to the lowest possible, my mac is very loud, so it must be the GPU fan. I also tried to hold my hand close to the GPU and I can feel that it's blowing like crazy.

    I also tried the mac fan control tool you suggested in that other thread, but it only shows the same fans iStat menus can control, not the GPU fan :/
  5. SteveJobzniak, May 2, 2016
    Last edited: May 2, 2016

    SteveJobzniak macrumors 6502


    Dec 24, 2015
    Mac: Mac Pro 2009 (4.1 updated to 5.1)
    Card: Gigabyte GV-N960WF2OC-4GD (rev. 1.1)
    OS: 10.11.4 (15E65)
    Driver: 346.03.06f01

    The graphics card fan never speeds up; it stays silent and very low-RPM at all times. It's always been silent, even when I was on 10.11.1, 10.11.2, 10.11.3 etc. Also on 10.10 Yosemite.

    But the Mac Pro is not meant to be upgraded with 3rd party graphics cards, so the Mac Pro's onboard fans are tuned for the low-wattage cards that originally shipped with it. When I replaced my GT120 with this new card, the PCI fan (the big gray one blowing from the front onto the PCI slots) and the PSU fan both speeded up and sounded like wind turbines.

    I needed to use Macs Fan Control to force the Mac Pro fans to react to temperature instead of wattage.

    The graphics card fans were never a problem.

    So about your problem:
    - Look in Macs Fan Control. What's your current speed for PCI and PS? Compare to mine (attached screenshot); I'm at the lowest possible speed. If I shut down Macs Fan Control the fans speed up insanely and become super loud, because the machine's own fan behavior is poorly tuned (see this post which claims it's because the Mac Pro reads a high wattage from the modern graphics card and thinks lots of cooling is needed, because the SMC onboard fan controller on the Mac Pro stupidly uses the wattage to control PCI and PSU fan speeds, instead of temperature: So I need Macs Fan Control for as long as I have 3rd party cards. I am 100% sure you will need Macs Fan Control too, because "high PSU power usage = high fan speed" is a behavior of the Mac Pros that must be fixed manually, and your 980TI draws a lot more than my 960.
    - If it's really your card that is noisy (too), then maybe certain graphics cards expect a windows driver for its fan control? Possibly it goes to 100% speed if Windows is not loaded.
    - There are no Mac utilities that can control graphics card fan speed. That's a proprietary vendor thing, and vendors only make utilities for Windows...
    - So if your card needs Windows drivers... ouch. :-( Can you exchange it?

    Attached Files:

  6. h9826790 macrumors G4


    Apr 3, 2014
    Hong Kong
    It's a known bug. Try quite MacsFanControl and run Lexmark for 10-15s or any benchmark that can stress the card. Then your PCIe and PSU fan should back to normal idle.

    Use MacsFanControl is an easier / more automatic method (after the initial setup), but not 100% required.
  7. norda72 macrumors newbie


    May 27, 2016
    Bollnäs, Sweden
    Same problem here with my Mac Pro mid 2012. Directly after startup the fans begin to speed up. The card I have is an Nvidia GeForce GTX 680 2048 MB. I have the fan controlling programme mentioned here, but I am afraid that the heat will increase if the fans are forced to work in a lower speed.
    I think I have to change this machine to a normal PC with Windows. The truth is that Macs are odd computers and Apple has not even 10 percent of the market with their computers.
    Or I have to change back to the ATI Radeon HD 5770 which is made for the machine. From the beginning this computer has had problems with whining and now it is even worse. Can it be the power supply that causes the noise? Right now I hear a whining, almost beeping sound.
  8. SteveJobzniak macrumors 6502


    Dec 24, 2015
    @norda72 Do not worry, the reason the fans go nuts on modern GPUs is because Apple has incorrectly programmed their fan firmware. It's literally a bug in their Mac Pro firmware.

    Their firmware says something like:

    FanSpeed = GPU Watt * 0.5.

    So the more watts a GPU uses (modern uses more), the more fan speed you get. It is a VERY STUPID algorithm and it has nothing to do with real heat. Their stupid algorithm works fine for the cards they sold, but goes bananas when given a modern GPU.

    The MacsFanControl program lets you control it manually and set good limits. Look at my thread about all of this.

    It's in my signature. Here: Fix Mac Pro fans when using PC (non-EFI) GPUs

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