AMDGPU vs. Radeon Kernel Driver Performance On Linux 5.0 For AMD GCN 1.0/1.1 GPUs

So generally switching to the AMDGPU kernel driver rather than Radeon DRM does slightly enhance the performance over the default Radeon DRM. Again, on any recent kernel it can be done easily via kernel command line parameters where as long ago it required Kconfig switches.

And besides being slightly faster, using AMDGPU as the kernel driver allows the RADV Vulkan driver (and AMDVLK) to function, which can then run newer Vulkan-only Linux games... Assuming your GCN 1.0/1.1 graphics card is fast enough in the first place.