With Ubuntu trying to improve their OpenGL driver support state to push the Linux OS as a platform for gaming, Valve going to be promoting the closed-source NVIDIA and AMD drivers on Linux, and various other challenges still turning up for those trying to use the different Linux OpenGL drivers, here are some new benchmarks comparing the open-source Radeon Gallium3D driver against the closed-source AMD Catalyst driver.
Ubuntu 12.10: Open-Source Radeon vs. AMD Catalyst Performance @ Phoronix.com