Thats so weird. My timedemo.. obviously is around 34 fps average, but thats at 1280x960. In-game play is fine now, Ive managed to get most way through the campaign with no real slowdown issues. I had to turn off shadows and that other option, but the game seems to look decent. If I turn on AA and AF it slows WAY down. Oh well, multiplayer is usually fine and the campaign is ok now so it works. Halo PC wasnt all I had hoped it would be though!!