Well..... Techtool Lite 3.0.4 was installed to see if the ibook would then rebuild the desktop as fast as my old original 233 imac does and it didn't help. The 600 ibook is much slower than the 233 imac in the desktop rebuild and also in using Norton 6.0 Utilities. Do these chip numbers actually mean anything ? The 233 imac was one of the first sold in the state years ago and for some applications it's as fast or faster than the 600 ibook. The imac has 288 MB memory, the ibook has 384 MB memory, so that can't be it. Puzzling..... - Bill K.