AMDGPU+RadeonSI Is Much Faster Than The Old Proprietary Fglrx Driver

ET: Legacy was among the few games not seeing any real change in performance between drivers, but this open-source game is CPU bound anyhow at 1080p.

OpenArena meanwhile was of the rare cases showing a performance regression with the newer open-source stack compared to fglrx, but anyhow the frame-rates are still in the hundreds.

Tesseract was also showing the AMDGPU+RadeonSI stack not living up to the full potential compared to fglrx for the HD 7950 / R9 270X / R9 285, but on the R9 Fury is 17% faster over the past two years.