Re: Starcraft unplayable on my nvidia - but works OK(ish) on Intel card
By default (if you don't touch any of the registry keys) rendering of starcraft is a very inefficient operation. In short the game uses 8bit rendering which means that on a 24bit desktop all rendering commands need to be converted. I doubt it is really the videocard which is important as all of this is done in software. What matters a lot is the cpu being used and how much cache it has. On my old radeon 9000 based laptop (it uses a p-m 1.3GHz with 1MB cache) it was a lot faster in software than on a dual core x2 3800+ mainly due to cache (I tried different cards).
When running in opengl mode the readtex mode on geforce-geforcefx cards works differently then on which we use GL_ARB_fragment_program if it is available. The code is quite different and a regression might have happened as the code has changed a lot. E.g. try Wine 1.0.1 to see how it worked there.