Radeon Gallium3D Performance Gets Close To Catalyst On Ubuntu 14.04

With Mesa 10.1, the Radeon Gallium3D drivers can now handle Unigine Valley/Heaven thanks to the R600g and RadeonSI drivers supporting OpenGL 3.3. However, the open-source drivers don't yet support OpenGL 4 tessellations or other more advanced visual functionality that's optionally supported by the latest version of the Unigine Engine.

When trying to run Unigine Valley on the RadeonSI driver, all the available graphics cards would fail due to LLVM register allocation errors within its Radeon GPU LLVM back-end. These issues are worked out in the newer code but not what's currently found "out of the box" in Ubuntu 14.04 LTS. For the R600g hardware, the numbers were good but again the Radeon open-source drivers don't yet support tessellation, etc.

For the Xonotic tests with high image quality settings, the open-source Radeon driver results for both Gallium3D drivers were close to 90% the speed of Catalyst though the game was more CPU bottlenecked than GPU limited.

With Xonotic at ultra and ultimate image quality settings, there were again LLVM register allocation issues with the Radeon GPU LLVM back-end in the "out of the box" Ubuntu 14.04 LTS configuration.