ACEFOMIQUZ wrote:In fact,i really don't know why IBM had developed such a low efficent 64-bit processor for taking place the past generation 32-bit processor.
Do you want to say there is the same thing that happening on the POWER architecture?POWER32<POWER64
I can't speak to true POWER chipsets. Their architecture is different from PowerPC.
As for why the first generation ppc64 chipsets were designed like that? I think - stress think - it might be due to power (i.e. wattage) consumption. The Power970 line - i.e. the Apple G5 - were architected down from IBM POWER4 chipsets, not designed by Motorola like the previous generation PowerPC 7400 series - i.e. the Apple G4.
From here:
http://en.wikipedia.org/wiki/PowerPC_970The 970 family was created through a collaboration between IBM and Apple. The project went under the codename GP-UL or Giga Processor Ultra Light, where Giga Processor was the codename for the POWER4 from which the core was derived. When Apple introduced the Power Mac G5 they stated that this was a five year collaborative effort, with multiple future generations, but it was short-lived. Apple had to retract the promise to deliver a 3 GHz processor one year after its introduction and IBM could never get the power consumption down far enough for these processors to fit into a portable computer.
and here:
http://en.wikipedia.org/wiki/PowerPC_G4Much of the 7400 design (aka G4) was done by Motorola in close co-operation with Apple and IBM. IBM, the third member of the AIM alliance, did design the chip together with Motorola in its Somerset design center, but chose not to manufacture it, because it did not see the need back then for the Vector Processing Unit. Ultimately, the G4 architecture design contained a 128-bit vector processing unit labelled AltiVec by Motorola while Apple marketing referred to it as the "Velocity Engine".
Now - the interesting question is "Where did the Cell's PPE come from?" The way I interpret the book "The Race For A New Game Machine", by Shippy, et al, the PPE is not derived directly from POWER4. Shippy says that the Austin team was designing the PPE for Apple/Sony/Microsoft, and due to removal of "out-of-order" processing to make Sony & Microsoft's console deadlines, Apple jumped from the Austin design center to one of IBM's server teams for the G5.
I understand this IBM server team would have been the POWER4 team. The Austin team's PowerPC core would have been similar to the one used in the G4, not POWER4 based, if I understand the book correctly. (i.e. the difference between a PC team and a Server team, in IBM-speak)
So - it's conceivable that the PPE may handle 64 bit somewhat differently than the G5. However - I'd have to do more research to find out how.
Cheers,
Paul