>>> cpu0 at mainbus0: Version 0x8003 (Revision 0x0102), ID 0 (primary)
>>> cpu0: HID0 8410c0bc<EMCP,EICE,DPM,ICE,DCE,SGE,BTIC,FBIOB,ABE,BHT>
>>
>> MPC7447A?
>
> From http://www.macnews.de/gallery/displayimage.php?album=16&pos=19
> it looks like a 7447B.

from an overclocker who disassembled it:

http://www.cubeowner.com/forums/index.php?showtopic=9124