Re: Would you like to see a benchmark demo using PS3.0?
you're gonna need a complex lighting model to take advantages of bynamic branching, or you can apply a more strict limitation on those survived pixels(i.e. cull more unlit pixel, such as using a smaller radius on the light).
IIRC, nVIDIA said there're 2 cycles penalty for each jump in the pixel shader, and according to my own test earlier, the penalty is even bigger. That is to say, if your shader isn't complex enough, the number of culled instructions may be even smaller than the penalty.