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Drivers & Software

Adept II

Issues installing OpenCL from Ubuntu amdgpu 20.45

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)!

5 Replies

I was wondering if maybe you can help this other User who is having problems with his GPU Card enabling OpenCL in AMDGPU-Pro driver:

Journeyman III

I have been trying to install on Ubuntu 20.10 this version amdgpu-pro-17.40-492261 for a firePro 3d v5800 gpu.

sudo ./amdgpu-pro-install --compute

it seems that drm/drmP.h is non existent in the kernels 5.8.x, likewise drm/drm_global.h and drm/drm_os_linux.h.

This are used still by amdgpu-pro-dkms to try and build the module into the linux kernel.

Obviously it fails miserably.


There's a new version of amdgpu 20.45, build 1188099, but that version is still ignoring the no-dkms option.


I had success on installing openCL on ubuntustudio 20.10 (low latency kernel) from the previous version of the amdgpu drivers (20.40) with --no-dkms. I just had to boot twice, the first reboot froze on login, got better result on luxmark benchmark than the same PC running MacOs Big Sur. Everything seems to run flawlessly.


Sorry, double post, my mistake.