This a daemon to control the fan speed of Radeon video cards. Currently
it's only tested with an Radeon RX 580, it should work with all cards /
GPUs supported by the amdgpu driver.
ATTENTION: Changing the fan speeds of your video card may overheat or even destroy your card! This tool comes without any warranty. If it destroys your hardware, it's your and only your problem!
All GCN and RDNA based Radeon video cards offer two ways of fan control:
- Firmware: The fan is controlled by logic implemented in the video cards firmware. This mode is usually extremely conservative, most cards start at about 30% PWM and max out at 100% PWM somewhere around 75°C.
- Software: The fan is controlled by software. The video cards provides a fan curve to the software, but the software may ignore it and do whatever it wants.
The card starts in firmware mode. Under Windows the driver switches it to software mode as soon as the system has booted to the desktop. The Linux driver has no software fan control, so the card stays in firmware mode.
The Windows driver is rather conservative. It reads three tuples of GPU
temperature and corresponding PWM speed from the cards ROM. This is the
default fan curve: (tmp0,pwm0), (tmp1,pwm1) and (tmp2,pwm2) For
temperatures up to tmp0 the fan stays at pwm0, for temperatures
between tmp0 and tmp1 at pwm1, etc. The fan speeds up as soon as a
temperature point is reached and slows down to the next slower level if
the temperature falls about 15°C to 20°C under the next lower
temperature point.
We're taking a more aggressive approach: Up to tmp0 the fan stays as
pwm0. Between tmp0 and tmp1 it's set to linear interpolated values
between pwm0 and pwm1, the same goes to tmp1 and tmp2. Above
tmp2 it's always set to pwm2. The fan speed is increased as the
temperature rises and only decreased if the temperature has fallen by at
least 5°C. With this, the card is less noisy then under Windows, but the
temperatures are comparable.
There's one safety measure: The cards ROM defines a maximum temperature. If the GPU reaches this temperature, it will throttle to protect itself from damage. We're driving the fan at full speed if the GPU temperature is less than 5°C under the maximum temperature, regardless of the fan curve.
If your distro has a package you likely want to use that. A precompiled binary of the latest release can be found under the release tab at Github. To compile the program by yourself:
- You'll need
go1.12 or higher. - Run
go get github.com/yamagi/radeonfan/cmd/radeonfan. - The binary ca be found at
$HOME/go/bin/radeonfan.
Copy the binary were you want it and alter init/radeonfan.service to
suit your needs. Copy it to /etc/systemd/system, enable and start it
as usual.
- -card: Card to control, defaults to
card0. - -debug: Print fan speed changes.
- -pwm0 and -tmp0: First temperature / PWM tuple.
- -pwm1 and -tmp1: Second temperature / PWM tuple.
- -pwm2 and -tmp2: Third temperature / PWM tuple.
Can I use the default temperature / PWM tuples?
- Maybe, it depends on your card. The default values are rather conservative and should be okay for most cards with 0db mode. They may not work properly on cards without 0db mode.
Okay, were do I get the tuples for my card?
- They can be read from the cards ROM (also known as the BIOS). A good
starting point is the Techpowerup Video BIOS Collection, but not all
BIOS dumps have the tuples: https://www.techpowerup.com/vgabios/
https://github.com/amezin/powerplay-table-editor is able to read the fan tables for some GCN generations.