Motorola chip launch paves way for 1.5GHz PowerBook G4
MPC7447A adds SpeedStep-style tech, too
Motorola's chip division - soon to be spun off as Freescale Semiconductor - today updated its G4-class PowerPC processor, the MPC7447, taking the part to 1.5GHz and paving the way for one more PowerBook G4 update the line before its upgraded to IBM's 90nm G5 chip, the 970FX.
The new Motorola part is dubbed the 7447A and adds on-the-fly clock frequency adjustment, allowing system makers to run at reduced frequencies according to workload. The upshot is longer battery life. And there's now a temperature-sensing diode included to monitor die temperature, Motorola says.
At 1.42GHz, the chip consumes 20W of power, Motorola claims, which compares well to the 7447's 21.3W at 1.33GHz. The company also mentions a lower power version of the 7447A that consumes less than 9.3W at 1.167GHz, which seems no better than the old 7447's claimed 7.5W at 1GHz. The low-power 7447A has a core voltage of 1.1V; the regular 7447A runs at 1.3V.
Essentially, the 7447A is a revised 7447, itself a low-power version of the 7457. The 130nm 7447 is currently used by Apple in its PowerBook G4. The iBook is based on the older 7455. The 7447 is a trimmed down version of the 7457, losing the latter's support for external L3 cache. The 7457 and both versions of the 7447 contain 512KB of on-die L2 cache. All three are fabbed using silicon on insulator technology.
According to Motorola, the 1.42GHz 7447A is shipping in sample quantities to "selected customers" for $245 a go, in batches of 10,000 CPUs. Volume production was not confirmed, but is likely to be reached during Q2 or Q3, we'd say.
That gives Apple time to beef up its existing PowerBook G4 line one last time before switching to the G5 - a distinct possibility now that IBM has got the 90nm version out the door. If Apple chooses to go straight to the G5 with the next PowerBook update, the 7447A can always be used to give the iBook a performance boost. ®