# [solved] Nvidia GTX 970 - How Control Fan?

## jagdpanther

On older Nvidia based cards (ex: GTX 670) I could use nvidia-settings to control the fan speed.  (I want to be able to increase the default speed before running some heavy OpenGL software.)  On my new EVGA GTX 970 the fan speed is displayed in nvidia-settings but there is no fan speed control.  Any suggestions for setting the fan speed on a GTX 970?

(It is a dual-boot system, and in Windoze 7  I can control the speed.)Last edited by jagdpanther on Sat Jan 31, 2015 4:31 pm; edited 1 time in total

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## dweezil-n0xad

If you want to enable manual GPU fan controls in nvidia-settings, you need to set Option "Coolbits" "12" in your nvidia xorg.conf

It works on my MSI GTX 970: http://i.imgur.com/JlQo0Tp.png

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## jagdpanther

dweezil-n0xad:  Thank you.

I'll try this today.

Is that 'fix' documented somewhere?

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## dweezil-n0xad

http://us.download.nvidia.com/XFree86/Linux-x86/346.35/README/xconfigoptions.html

 *Quote:*   

> Option "Coolbits" "integer"
> 
>     Enables various unsupported features, such as support for GPU clock manipulation in the NV-CONTROL X extension. This option accepts a bit mask of features to enable.
> 
>     WARNING: this may cause system damage and void warranties. This utility can run your computer system out of the manufacturer's design specifications, including, but not limited to: higher system voltages, above normal temperatures, excessive frequencies, and changes to BIOS that may corrupt the BIOS. Your computer's operating system may hang and result in data loss or corrupted images. Depending on the manufacturer of your computer system, the computer system, hardware and software warranties may be voided, and you may not receive any further manufacturer support. NVIDIA does not provide customer service support for the Coolbits option. It is for these reasons that absolutely no warranty or guarantee is either express or implied. Before enabling and using, you should determine the suitability of the utility for your intended use, and you shall assume all responsibility in connection therewith.
> ...

 I was wrong, "4" is enough to enable only fan control. "12" is "8" + "4"   :Smile: 

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## jagdpanther

Thanks   "4" or "12" works well.  Also that documentation file, xconfigoptions.html is part of the portage nvidia-drivers package and is located at:  /usr/share/doc/nvidia-drivers-343.36/html/xconfigoptions.html

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