I hope all you realize that sm3 or sm2 or sm anything only applies to the shaders used in the game. I don't see how it would make any difference if the game was written with sm3 from the ground up or not, because shaders only make up a small part of the whole game engine. In fact, shaders are like separate short programs that run on the gpu, and they are written in a high level language and then compiled into either sm2 or sm3 code. As far as the rest of the game engine is concerned, it doesnt care which shader model is currently running. I've said it multiple times, and yet some people seem to think the whole game is like one huge shader or something. Is this so hard to understand?