http://www.phoronix.com/scan.php?page=article&item=wine_win7_2010
"With this testing we ran eight games/benchmarks natively under Ubuntu 10.10, the Windows binaries under the stable Wine 1.2.1, the Windows binaries under the Wine 1.3.9 development snapshot, and then finally under Microsoft Windows 7 Professional. The test profiles used had included OpenArena, Urban Terror, Warsow, Nexuiz, Lightsmark, Unigine Sanctuary, Unigine Tropics, and Unigine Heaven. The OpenGL renderer was used with all of them...
From this first round of 2010 Wine vs. Ubuntu vs. Windows 7 testing it
is tough to draw any conclusions. About the only conclusion to draw would be that you cannot draw any definitive conclusions about the Wine performance compared to the native performance on either Linux or Windows. ... Stay tuned for our expanded Wine testing and to see how the Linux performance compares with some more popular Windows-only Direct3D-rendered games."