Source: http://arstechnica.com/journals/apple.ars/2007/08/22/speculating-on-the-iphone-memory-footprint-and-cpu-speed According to that article provided, from what I understand the iPhone's ARM processor is 600MHz, but actually runs at 400MHz, (it's understandable when you incorporate battery life.) So anyways I want my iPhone to run at the speed it was built for, The battery isn't an issue for me, just because I have my plugged in a lot.. I always understand that it would overheat, I don't plan on doing too much graphical. Thanks. (iPhone running Halo...It's funny when people thought the Nintendo DS lite could do it..If the iPhone can't do it, THE DS CAN't! ) EDIT: OR DOES IT RUN ON 600MHz? Or is it underclocked the whole time?