Originally posted by Norman Terry
You also have to remember that IBM guesses at best what speed each batch of chips will run at. If they test ok at 2.0 then their 2's, 1.8 then 1.8's etc. Another thing to consider is that the 970 is stiil at .09 microns and when they reach the .07 micron mark here in the next few months they will be able to put the L1 cache to a full 1 MB which will also have Intel and Sunn at bey. As for the iMac eMac and iBook and Powerbook, they will all get G5's in due time, but first apple will have to use the remaining G4's which are supposed to go all the way to the 2 GHZ mark by the end of the year. the 1.5 GHZ PowerBook G4 is already in development and so is the 1.2 GHZ iBook and iMac.
Why would Apple need to use chips that they havent developed computer for, or purchased? As of today, the G4 maxes out at 1.4 Ghz for the 7455. I would Assume that Apple may have some of these chips on hand still, and might want to use them, but they could as easily liquidate the remaining stock of PM's with them.
As far as future G4's, the 7457 is rumoured to be about ready, just working up the fab process. According to PowerLogix this chip will have speeds of up to 1.6 Ghz when launched. Since they are developing a Dual 1.6 daughter card that they plan to release for the Cube I dont think heat will be an issue with these chips in the iMac using a single processor. Since PowerLogix has sample chips on hand I would assume that Apple has them as well.
See post by powerlogix
Following up my earlier post:
According to our inhouse testing, here is what we have found:
When comparing power dissipation between 1.4g 7455 and 1.4g 7457 during a CD RIP
in iTunes, the 7455 shows an additional 31.5 watt demand. Extraordinary.
For system idle in OS X, it measures 11.4 watts more.
Quake (comparing 1.2 gig 7455 to 1.2 gig 7457): 28 watts more for the 7455.
It would be a bad marketing move for Apple to stick with a 1.2 model iMac for the next revision if the 7457's were available at speeds up to 1.6, and these were released as upgrades for previous G4 computers. they would get eaten alive in the press and on the boards. Apple might be able to entice Cube and iMac owners to upgrade with a good speed boost with a top end 1.6 G4 but a 1.2 is not signifigant enough of a boost to get a lot of people excited enough about the new model to say "I need to upgrade now."