i was just wondering about the difference between the TiBooks system bus and a P4s system bus. i don't know much about this sort of stuff, so correct me if i'm wrong. is the reason for having a 166MHz bus because the current RAM can't keep up? if the TiBook had a faster system bus, would spend time waiting for the RAM? and if current RAM isn't that fast, why does the P4 have a 400MHz system bus? wouldn't the CPU just spend time waiting for the RAM to refresh?