7470 PPC and Why no G5's.
After publishing possible specs for upcoming PowerMacs, the discussions invariably return to G5s, with people holding out hope that G5's will be released "any day now". However... based on all available information, G5's are likely not expected until 2003 at least.
According to Motorola sources, a tweaked version of the Apollo 7450 G4, the 7470, will be ready for volume production shortly after the end of Q2, in time for a summer ramp. The 7470 will be manufactured on a 0.13 micron process, allowing for a smaller die size with room for 512K of L2 cache, and support up to 4MB of DDR-SDRAM L3 cache.
The 7470 supports a modified bus protocol, MPX+, which supports double data transfer and which should effectively run at 266Mhz according to sources.
The MPX+ bus retains MPX's 36-bit addressing lines, and is described as an interim measure. Don't expect dramatic leaps in SMP scaling - two will remain the sweet spot. The 7470 should scale to 1.5GHz. In parallel development, Motorola is priming a cut-down 7470, labelled the 7460, which doesn't support L3 cache.
In another report from Jan, 2002, MacCentral quotes Motorola on how the G4/Apollo chip still has a lot of life left in it:
It is important to note that this is only the first installment in this [G4] processor family. "The big news here is that this device is certainly not topped out," said Swearingen. Mac users can reasonably expect incremental performance increases from this processor family in the future, taking Apollo to its promised GHz+ performance levels.
While we'd like to tell you outlandish tales of teleporters and G6's... expecting true G5 processors "any day now" is setting yourself up for disappointment, based on available information. That being said, there were alternative rumors (Register), Architosh as well... and we'd love to be proved wrong.