Xonotic with high quality settings also yielded the best results on the Ubuntu 13.04 operating system that's still under development.
Overall, these results of the two latest releases of Ubuntu and Fedora are quite interesting. For both the Radeon and Intel drivers, the best performance overall is with Ubuntu 13.04. This next Ubuntu release is due out in April and already has a performance lead thanks to pulling in the latest Linux 3.8 kernel plus continued work by Canonical on improving the gaming performance when running under Unity/Compiz. Still to find its way in Ubuntu 13.04 is Mesa 9.1 that should yield greater performance and feature benefits for the open-source graphics drivers.
As the Ubuntu 13.04 release nears, additional OpenGL/gaming benchmarks of the popular Linux distribution will happen on a wider selection of hardware and driver configurations.