World of Padman runs about 9% faster on PC-BSD 8.2 over Ubuntu 11.04.
The 32-bit build of OpenArena was only 4% faster than when it was run on Ubuntu 11.04, but with the 64-bit build the margin expanded to 14%.
With the sample of Linux-native games and real-world OpenGL benchmarks used, PC-BSD 8.2 with its Linux binary compatibility support was faster than Ubuntu 11.04. This was for both the 32-bit and 64-bit versions of the operating systems. Additionally, both operating systems were using the same NVIDIA GeForce proprietary graphics driver release. On average the performance under PC-BSD/FreeBSD 8.2 was 8~14% on average, but BSD's lead expanded as the tests became more intense.
It would be interesting to see how Debian GNU/kFreeBSD performs in comparison for Linux gaming, since it just has the FreeBSD kernel and with a full Debian GNU user-land. However, at last attempt, the proprietary FreeBSD NVIDIA driver did not like Debian GNU/kFreeBSD due to the user-space differences. When I am back from the annual Oktoberfest pilgrimage, the investigation will continue.
Prost (cheers) to the FreeBSD developers for outperforming Ubuntu at Linux gaming.