I replaced my wife's blueberry 3 GB drive with an IBM GNX (5400 / 8 MB buffer) and it sure got a little snappier - of course I also maxed out the ram so not sure if the buffer is any big deal. I have a Toshiba 40 MB 5400 RPM with 16 MB buffer that is sitting in my drawer awaiting sufficient free time. I'll be putting it in my 500 ice book soon and will let you know. TransInternational is my source for both drives. I usually link to them from <http://www.dealmac.com> Dan (i am wondering if hd buffer size will make that much > difference in system speed on the ibook... any hd suggestions?