Be carefull with chip-specific but manufacturer-generic drivers. Sometimes they work great, sometimes they make things slower, and often they give a slight increase in performance balanced by a major hit on stability.
The Detonator drivers have been notorious amoungst the testers I know for creating incompatibility problems with some games.
The biggest problem is that once you install a driver on Win9x, 'uninstalling' it and reinstalling a older driver doesn't always work the way it should. Usually things function, but the driver settings can get confused and you can wind up with a very unstable system.
I strongly recommend getting GHOST or PQDI and creating a backup image of your HD before you muck with non-manufacturers drivers.
Thog