Apple could well hold fire on Power Mac G5s until after Macworld Expo, San Francisco, news reports claim.

A Motorola spokesman told MacCentral yesterday that Motorola is preparing to ship its next-generation G4 processor (Apollo) in early 2002.

Apollo is manufactured using Motorola's SOI (silicon on insulator) technology. Motorola's current crop of G4s are manufactured using a copper-fabrication process. SOI offers a 20 to 30 per cent performance gain when compared to that process, MacCentral claims. SOI-produced processors run cooler while consuming less energy - so higher clock speeds, or MHz speeds, are possible.

Chip pundits claim Apple's G5 processor is unlikely to be imminent when such a highly specified G4 chip is set to become available so soon.

Motorola's David Bearden, senior member of technical staff at Motorola's Design Center, told the Microprocessor Forum last year: "Apollo is set to run at GHz+ speeds."

The conclusion supports comments made to Macworld UK last week. Paul Clark, Motorola's European marketing communications manager, wanted to minimize speculation of a G5 Mac. He claimed the potential of the G4 architecture has exceeded expectations. "There's a great deal of headroom left in the chip, which still has enormous stability," he said.

Apple will end the speculation one way or the other at the Macworld Expo, San Francisco, 2002. The event runs from January 7-11, with a keynote speech on Tuesday, January 8.