What means "it is not the PowerPC"?
It is most certainly a PowerPC (G5) machine if it is an Apple.
THe question is whether it is a dual Processor machine produced before Oct 19. 2005, or a dual-core machine produced after Oct 19 2005.
If it is a dual G5 2.5 GHz, then it is most likely the Dual Processor, June 9, 2004 - April 27, 2005 with 8 RAM sockets
Also FYI, there is no Powerbook Pro, the name was introduced as MacBook Pro.