Phoronix: FreeBSD: A Faster Platform For Linux Gaming Than Linux?

FreeBSD provides a Linux binary compatibility layer that allows 32-bit Linux binaries to be natively executed on this BSD operating system. Linux binary compatibility on FreeBSD allows Linux-only applications to be executed in a near seamless manner on this alternative platform, even for games. New tests have revealed that the modern FreeBSD operating system (via PC-BSD 8.2) can actually outperform Linux when it comes to running OpenGL Linux game binaries.

http://www.phoronix.com/vr.php?view=16382