Check boot messages for more information about the graphics card driver in use
Check clockspeed and other info
Run a program on your dedicated AMD graphics card
https://amdgpu-install.readthedocs.io/en/latest/
https://www.x.org/wiki/RadeonFeature/
https://help.ubuntu.com/community/AMDGPU-Driver
https://help.ubuntu.com/community/RadeonDriver
https://repo.radeon.com/amdgpu/
https://en.opensuse.org/AMD_OpenCL