"How can I track GPU temperature and fan speed, and adjust the latter?"
Radeontop is a good place to start.
"Radeontop is a small utility which allows one to monitor the utilization of
Radeon GPUs starting from the R600 series and newer using undocumented
performance counters in the hardware. The utility works with the free drivers.
It displays the utilization of the graphics pipe, event engine, vertex
cache,vertex group and tesselator, texture addresser and cache, the shader
units and more, both with a relative percent value as well as a colorful bar
diagram."
Reference - Synaptic package manager - Debian Buster
A starting place for fan speed control.
"Seems like you need to be able to create a custom fan curve. Try Corectrl,
rather simple and has gui."
just image from internet but corectrl gui
Add PPA
sudo add-apt-repository ppa:ernstp/mesarc
Update
sudo apt-get update
Install Corectrl
sudo apt install -y corectrl
Reference -
https://askubuntu.com/questions/1394954/how-to-control-amd-gpu-fan-speed
