Originally posted by Phil Of Mac
And it's a G3...without AltiVec...
Correct. If you often use applications tuned for AltiVec, there's no argument that a G4 is better.
That aside, for non-AltiVec applications the 750FX "G3" in iBooks are already neck-and-neck with the "G4" in PowerBooks of the similar clock speed, and that's with the former having the disadvantages of a lower FSB speed and weaker graphics chip. So the 750GX, with its bumped up cache (1MB) and clock speed (up to 1.1GHz), combined with the bumped up FSB and better graphics chip the new iBooks have received, could have proved slightly embarassing for the PowerBooks.
If you use Mac OS X it all comes down to how much AltiVec you use, but being a Linux user myself that is insignificant and I would've preferred the lower power consumption of the 750GX (<8W typ. @ 1GHz) and longer battery life that would result.
Rincewind, you may be right, but when I looked it didn't add up. The 7445/7455 spits out 17W typ. @ 800MHz (24W max) according to the specs. How is the 6 hour battery life being maintained? Where is that heat going on a 12" iBook? The internal metal frame is insulated by plastic, so it's not radiating like it could with the PowerBooks. This was my first thought the new iBook was unveiled--the G4 might kill its reputation as a cool and mostly silent machine (unless you're one of the unlucky ones stuck with an iBook G3 with a constantly running fan).
On the other hand, the first impressions article at xlr8yourmac.com, while not going into much detail, said "Subjectively it feels no warmer than a 700 MHz iBook" and had good things to say about the battery life.
These are the things that lead me to guess that it uses a neutered 7447/7457, but it's also possible the iBook G4 uses a
new revision of the 7445/7455 with lower power consumption. There is a recent sales document at Motorola which lists significantly lower power specs than the 7445/7455 product summaries, indicating the figures from the latter may be out of date. It gives the 7445/7455 a figure of 11.2W typ. @ 800MHz. These new Rev F/G's weren't due for production until June/July this year, so they would not be the same old G4's leftover from the previous range of PowerBooks, as some have speculated.
Sorry about the long post, but hopefully you can see I didn't make my speculation out of thin air
