But you need to load amdgpu drivers for Ubuntu.
They will not install without patch.
But you don't need to install it, just some dpkg's from all archive.
1. Install Debian drivers with, apt as was shown here in tread.
2. Load amdgpu for Ubuntu, tar -xvf it.
3. Install:
dpkg -i opencl-orca-amdgpu-pro-icd_20.45-1164792_amd64.deb
4. Install:
dpkg -i ocl-icd-libopencl1-amdgpu-pro_20.45-1164792_amd64.deb
5. After that just run teamredminer(in my case), and see that it correclty finds all GPU's
I have 2 old rigs with same hardware setup on RX 470 4Gb
One is Ubuntu 20, second is Debian 11.
Both show equal hashrate.
PS. Ahh... not mentioned...
I was able to make full-setup of amdgpucore on debian(with patch) and ubuntu.
But here was an error - when you try to
echo 'something' > /sys/class/drm/cardX/device/pp_od_clck_voltage'
So I was revetring both PC's to pure Debian/Ubuntu firmware and then installing only needed packages as show above.
Not know if this was fixed in next releases.
You have missed one big point his issue is not with the old videocard but with the RX 5500 XT and to use that card you need to have the opencl rocr (rocm) installed. Your instructions are just for older videocards.