G4 iBooks

fryke said:
There's only a link in the back of the document that _links_ to Motorola's latest G4 pages (7457/7447), which clearly says that the 7457 has 512K of L2 on-chip cache. The iBook has 256K (7455). So I guess it's just a false URL used in the tech document.
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There is a link to this page under Supplemental Documentation: http://e-www.motorola.com/webapp/sps/site/prod_summary.jsp?code=MPC7457&nodeId=018rH3bTdG8653 , which is specifically about the PPC7457. I believe they mean to link to the PPC7447 though, which is a better fitted processor for the iBook than the PPC7455.
 
The 7447 also has 512K of L2 cache on chip. So, no: It's quite clearly a 7455.
 
fryke said:
The 7447 also has 512K of L2 cache on chip. So, no: It's quite clearly a 7455.
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There's no way they'd use the 7455 now, with the availability of the 7447/7457, which are more than 3.5 times more power efficient.
They could put a G5 in the thing with less heat dissipation.

You know, Motorola's docs also say the highest PPC7455s are 1 GHz, although Apple have these running at 1.42 GHz. Apple have special designed chips to suit their needs.
 
Power efficiency doesn't factor into this. The iBooks are cheap, and Apple would probably place an older processor into the iBooks to keep the price point down. Now that new methods of chip fabrication have come about, the older chips get easier and cheaper to produce.

It's highly likely that Apple used an older G4 processor in the iBook.
 
ElDiabloConCaca said:
Power efficiency doesn't factor into this. The iBooks are cheap, and Apple would probably place an older processor into the iBooks to keep the price point down. Now that new methods of chip fabrication have come about, the older chips get easier and cheaper to produce.

It's highly likely that Apple used an older G4 processor in the iBook.
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Power efficiency is a major factor in any laptop. Especially the current iBook design, because of its relatively small battery and inefficient cooling. It's pretty obvious the current iBooks aren't made for processors dissipating as much heat as the last titanium PowerBooks. A magnesium frame with a plastic shell isn't that much of a heat sink.
 
I'm quite sure that the 7455 that was used in Titanium PowerBooks at up to 1 GHz is the chip used in the new iBooks. Those processors didn't seem much too hot back then, they don't seem now. There are A and B variants of 7455, too, btw., and I also think that there is a lower power variant that is used in the iBooks (and was in the TiBooks). You are aware that the 1 GHz PowerMacs needed quite a bit more cooling than the TiBooks at 1 GHz, right?

We'll just have to wait until someone takes apart a new iBook (and some Japanese guys will, as I've said about the new aluBooks before and was right...) to definitely know, but the cache size gives it away, really.
 
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