The Linux 3.12 kernel when released in the coming weeks will bring a number of new features and improvements to AMD Radeon graphics cards, including faster performance. For many Linux games tested the Radeon Gallium3D OpenGL frame-rates were making double-digit gains through upgrading the Linux kernel.
There's several AMD Radeon DRM changes in Linux 3.12. Among the highlights for this next Linux kernel release includes Radeon HD 8000 "Sea Islands" Dynamic Power Management (DPM) and Active State Power Management (ASPM) support, support for AMD "Berlin" APUs that are based upon the Radeon GCN architecture, a major ring handling clean-up, removal of old 3D blit code to now handle buffer object moves with the CP DMA / sDMA engines, and lots of bug-fixes.
Likely due to the change how buffer object moves are happening, the OpenGL performance for Radeon GPUs is faster with the Linux 3.12 kernel. With benchmarking done today from an AMD Radeon HD 4870 "RV770" graphics card with Mesa 9.3 Git and running Ubuntu 13.10, on the following pages is a large Linux kernel comparison looking at the Radeon DRM performance. Benchmarked were the mainline Linux 3.7, 3.8, 3.9, 3.10, 3.11, and 3.12 Git kernels on Ubuntu 13.10 from our Intel Core i7 4960X EE system.