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

A seldom advertised experimental feature of the AMDGPU kernel driver has long been the GCN 1.0/1.1 graphics support. By default these Southern Islands and Sea Islands graphics processors default to the Radeon DRM driver, but with some kernel command lime parameters can use the AMDGPU Direct Rendering Manager driver. The AMDGPU code path is better maintained since it's used for all modern Radeon GPUs, using AMDGPU opens up Vulkan driver support, and possible performance benefits. It's a while since last testing the Radeon vs. AMDGPU driver performance for these original GCN graphics cards, so here are some fresh benchmarks using the Linux 5.0 kernel and Mesa 19.1-devel.