13-Way R600/RadeonSI GPU Comparison With Mesa 10.1 On Ubuntu 14.04
Xonotic with ultra (and ultimate) image quality settings also failed for the hardware using the RadeonSI Gallium3D driver, again due to LLVM register allocation issues.
The high-end AMD Radeon hardware from the Radeon HD 4890 and forward were able to push above a 60 FPS average with ultimate image quality settings at 1920 x 1080.