I'm installing the OpenCL driver from amdgpu-pro on Ubuntu 20.10. Because I'm installing OpenCL on kernel 5.8, I don't want to build kernel module amdgpu, as this will fail. That's why I'm installing it like so:
amdgpu-install --no-dkms --headless --opencl=rocr
This is working well with amdgpu-pro 20.40, but 20.45 is just ignoring the --no-dkms part, and tries to create, and install the module anyway. This of course fails in this case. To add insult to injury, because the module fails to build, it will blacklist amdgpu, causing Ubunto to use the wrong driver, and screen resolution on reboot! However it does install OpenCL, so after it has failed I remove amdgpu-dkms, and the blacklist. OpenCL then actually is working.
I understand a new feature of 20.45 is the backend, it's no longer PAL, it's now ROC. Unfortunately this means that this new driver has inherited an issue that occurs with ROC. ROC, and now 20.45 as well, will render the benchmark LuxMark 3.1 incorrectly if compiler option cl-fast-relaxed-math is enabled.
Even if you disable the option, ROC will run quite a bit slower, I get 15 MRays/sec, and a score of 2800. With 20.40 there's no need to disable the option, and I get 30 MRays/sec, and a score of 5800. So 20.40 is twice as fast as 20.45 (and ROC as well)!
