I Think you add it as a switch, so right click on the shortcut and go into properties and add the -forcegpu ati_r700 into the target fiel, for example:
2v10? wth?? I feel ya on the rusty part, haven't played in a while and just did a 3v3 a couple days ago. Both my partners left the game and I got schooled, but what can you expect for a 3v1?? You follow any of the pro gamers? Some pretty epic replays on YouTube casted by Husky.