I was a little disappointed that I was only getting about 30 FPS in half-life 2 on my 2011 macbook pro 15", but at some point I accidentally left gfxCardStatus set to "Integrated Only". Then, when I played the game, my FPS was consistently between 90-140fps with the same settings (everything maxed besides some filtering stuff). When I put it back to discrete, the FPS shot down. Why could I possibly get so much better performance on a theoretically inferior graphics processor? Also, this is the low end 15" with the crappy (but still supposedly better than integrated) graphics card.