Edit: see also Radeonsi is faster than Catalyst with Steam games.
I did some benchmarks of my AMD Radeon HD 7950 using kernel 3.15-rc4 + PTE patches (VRAM page table entry compression) + hyperz (R600_DEBUG=hyperz). I’m also using libdrm git, xf86-video-ati git, llvm 3.5 git, mesa git (OpenGL core profile version string: 3.3 (Core Profile) Mesa 10.3.0-devel (git-cf93f86)) and Keith Packard’s xorg-server glamor-server branch (1.16.0 RC 2). Catalyst version is 14.4 (kernel 3.14.3, xorg-server 1.15.1).
Radeonsi is 14% faster than Catalyst with Xonotic.
Radeonsi is 4% faster than Catalyst with Openarena.
Radeonsi runs at 76% of Catalyst with Unigine Heaven.
Radeonsi runs at 62% of Catalyst with Unigine Valley.
Something’s wrong with radeonsi and Unvanquished, it’s barely 30% of Catalyst.
Here is the link on openbenchmarking: http://openbenchmarking.org/result/1405084-SO-1405083SO83
I also compared 2D acceleration using Keith Packard’s xorg-server glamor-server branch between radeonsi, Catalyst and Intel’s HD 4000 SNA: http://openbenchmarking.org/result/1405080-SO-1405080SO26
Intel’s HD 4000 SNA 2D acceleration is much faster in almost every test compared to both Catalyst and radeonsi, but glamor is much faster using Keith Packard’s xorg-server glamor-server branch compared to the old standalone glamor lib.