"Sources close to Apple familiar with the new machines said that, contrary to industry rumours, the new PowerBooks will not breach the psychologically important 1GHz barrier, due to problems with cooling and battery life. Instead the fastest PowerBook will be 933MHz (up from 867MHz) and the entry level 667MHz model will be speed-bumped to 867MHz.

The system bus will continue to run at 133MHz, rather than moving to the 167MHz motherboard introduced with the current top of the range Power Mac G4s, said the sources.