AMDGPU vs. Radeon DRM On Linux 4.13 For AMD GCN 1.0/1.1 GPUs

With the Linux 4.13 kernel currently under development there are new module parameters that can make it easier switching from the Radeon DRM default on GCN 1.0 and GCN 1.1 GPUs to instead using the newer AMDGPU DRM driver, but Radeon remains the default. Here's my test experiences and benchmark results of AMDGPU vs. Radeon for GCN 1.0/1.1 GPUs.