README.md

nvidia-fan-controller

PWM chasis fan controller for Nvidia Tesla GPUs.

Controll the chasis fans based on the temperature of the GPU.

How to make it run?

Make sure that the the path defined in const char *fan_file = "/sys/class/hwmon/hwmon2/pwm2"; points to the right fan of your system. pwmconfig is a useful tool to identify the fans.

The file is compiled using:

 nvcc nvidia-fans.c -o nvidia-fans  -lnvidia-ml

In order to run it as a service, create the file /etc/systemd/system/nvidia-fans.service with the following content

[Unit]
Description=Nvidia fan controller

[Install]
WantedBy=multi-user.target

[Service]
Type=simple
ExecStart=/usr/local/nvidia-fans
WorkingDirectory=/usr/local
Restart=always
RestartSec=5
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=%n

Make sure to ExecStart points to the location of the executable (nvidia-fans can be made executable with chmod +x nvidia-fans). The service is started with

systemctl enable --now nvidia-fans.service

Details

The following is the characteristic curve for the controller. The varibles cand be adapted in the code.

^ (pwm)       
|
|    (tmax,fmax) ,------
|               /
|              /
|_____________/ 
|             (tmin,fmin)
|------------------->  (temp)   

Moreover, a hysteresis behaviour is implemented: the fan speed decreses with a delay. The delay is a multiple of delta_t and can be adapted in max_relax.