I'm not sure what will fit into the ibooks and powerbooks, but I know for sure that a 7200 RPM drive in my Fujitsu notebook ran considerably faster than the 4200RPM, with a negligble power loss. And even if there was a little power loss, the 7200 RPM drive is absolutely amazing and well worth it. The one I have is the Hitachi 7K60 or something like that. --- You wrote: hello list members i'm new to the list and wanted to ask a question regarding upgrading hard drive in my ibook g4. I was wondering if it would make a big difference in battery drain by moving from my original 30gb drive to an 80 gb 7200rpm drive Thanks in Advance Richard --- end of quote ---