For the Radeon system's benchmarking of the Fedora and Ubuntu releases, OpenArena (both 0.8.5 and the more demanding 0.8.8 release) and Xonotic were tested at 800 x 600, 1024 x 768, 1280 x 1024, 1680 x 1050, and 1920 x 1080 resolutions for the Radeon HD 4650 graphics card atop the open-source R600 Gallium3D driver stack.
For OpenArena 0.8.5, Ubuntu 13.04 was the fastest release at the two lowest resolutions (800 x 600 and 1024 x 768) while at 1280 x 1024 and above, the Ubuntu 13.04 Radeon performance was just in line with Fedora 17 and Fedora 18. Ubuntu 12.10 and its default graphics/OS stack were much lower than the three other opearing systems.
OpenArena 0.8.8 had problems running on the Ubuntu 13.04 daily installation, but the three other operating systems worked fine. Interestingly, Fedora 17 was faster than Fedora 18 at every resolution tested. Ubuntu 12.10 was much slower than the two Fedora Linux releases.
With the Xonotic open-source first person shooter, Ubuntu 13.04 was much faster than Fedora 17/18 and Ubuntu 12.10. Ubuntu 12.10 meanwhile was the slowest. This is a very significant gain for Ubuntu Linux simply over the past six months. When Mesa 9.1 is integrated into Ubuntu 13.04, the frame-rates should go up even more for the Radeon Gallium3D driver.