here's the command to change fan speed on a single GPU:
nvidia-settings -a [gpu:5]/GPUFanControlState=1 -a [fan:5]/GPUTargetFanSpeed=70
This will set fan on GPU5 to 70%. Change as you see fit, however note that if you have Maxximus007_auto_temp control enabled, it will readjust it back on its regular cycle.
That's the response that i recieve :
sudo nvidia-settings -a [gpu:0]/GPUFanControlState=1 -a [fan:0]/GPUTargetFanSpeed=30
Failed to connect to Mir: Failed to connect to server socket: No such file or directory
Unable to init server: Could not connect: Connection refused
ERROR: The control display is undefined; please run `nvidia-settings --help`
for usage information.
Are you executing this in guake terminal while locally logged in or are you loging in trough ssh?
to turn off access control. Once done issue "xhost -" to turn access control back on. By the way, you don't need sudo for nvidia-settings.