Thanks to shaderboy for the info:

Unwinder, the author of RivaTuner has published his report on the NV and ATI antidetector he has been programming. The antidetector blocks all optimisations and cheats in graphics drivers.

The article only covers 3DMark2001SE. The results are interesting. Both ATI and Nvidia lose points, ATI in game 4 and Nvidia in game 4 and Dragothic. ATI lose 385 points Nvidia 1243!

Nvidia And ATI: Anti - Detector Review