The Unigine Engine is rather fascinating as it's capable of delivering impressive graphics, their developers are rather friendly to Linux, and its the most demanding game engine that we have ever encountered for Linux (though soon it will need to compete with Valve's Source Engine running natively on Linux). We began using Unigine's oldest tech demo (Unigine Sanctuary) that is produced for Windows and Linux.
While by rather insignificant margins, Ubuntu 10.04 LTS was faster than Windows 7 in many cases. If you look at the results, where Ubuntu is pulling ahead is when the ATI Catalyst driver is being called into play with the Radeon/FirePro hardware. On the systems with NVIDIA graphics and their proprietary driver, its performance was usually slightly behind on Linux. The Intel Clarkdale graphics are not fast enough to handle the Unigine engine.