The Qfusion-powered Warsow game produced similar results to the ioquake3-powered Urban Terror game. The Windows 7 graphics performance was flat while Ubuntu Linux started out faster but by the time of hitting 1920 x 1080 the performance was dead even between the two operating system drivers.
The most demanding OpenGL test in this article is Nexuiz and here the Mesa 7.10-devel + Linux 2.6.37 kernel DRM struggled to compete with the proper Intel Windows 7 driver. On average, the Windows 7 driver was 56% faster than the open-source Mesa driver was and the gap widened at the higher resolutions.
The latest Intel/Mesa driver code on Linux has resulted in some performance improvements and has made it more competitive with their Windows graphics driver, but still we are finding the Intel Linux performance to be at a loss in the more demanding test environments. The Intel Windows stack is also compatible with more games and OpenGL applications than the Mesa-based Linux solution. It will be interesting to see how the Intel Sandy Bridge performance compares between Microsoft Windows and Linux once released early next year.