My current GPU is an old AMD HD 7850 and I had been really happy with its performance using the radeon driver. Whenever I made a fresh install of the OS, it always worked out of the box. I played every game that I wanted with no issues, and with some tweaks, I got solid 60 fps almost every time.
But recently, after updating my kernel to 4.20, I had encountered game breaking issues with the combination of the radeon driver and the mesa library. Particularly using the dolphin emulator (I was playing Metroid Prime with mouse and keyboard). I started getting hard crashes, even kernel panics from time to time. I always use stable versions of mesa, but this time, I also tried the bleeding edge versions and the issue continued. It seems that is a problem with the radeon driver and recent versions of mesa. I had used the last release of dolphin (5.0) for a lot of time with no problems until this. I also compiled the latest development version of dolphin, but the issue was still present.
Also, Warframe stopped supporting Directx9 as of February of this year. The radeon driver does not support Vulkan, so I could not use DXVK to play the game.
At this point I was decided to purchase a new GPU. But then, I read that the amdgpu driver added “experimental support” to the GCN 1.0 architecture (or the Southern Islands family; The HD 7850 is a Pitcairn chip) some time ago. I edited my grub file, adding radeon.si_support=0 radeon.cik_support=0 amdgpu.si_support=1 amdgpu.cik_support=1 to the GRUB_CMDLINE_LINUX_DEFAULT parameter, updated my grub and restarted my system.
It works! The issue with dolphin is gone. Now I am playing Warframe using DXVK and with some tweaks I am getting between 55 and a hundred frames per second (yes, the framerate is all over the place, but if I do not look to the FPS counter, I hardly noticed it).
Thanks to the amdgpu driver I can hold a little bit more the purchase of a new GPU.
The radeon driver achieved amazing performance and stability, but I think that it is not getting the same amount of attention as before, and it is obvious, it was created to support hardware that almost everyone has already replaced.