I have ATITool .27 for windows vista and I'm slightly scared to use it but I know I need some sort of system speed increase for my Graphics card. The problem is that I don't know how to use the programme at all! I assume you must find the highest values with the "Find Max" tests and then set the speeds yourself. In the little dropdown box it says my default is 89.95/89.95 Arent iMacs supposed to be in excess of 400/400 or something? I also noticed that you can set the speeds up to 2000/2000 I guess that is dangerous? I'm running an iMac Core2DUo 20" stock with Vista in Bootcamp.