Originally Posted by Buio
If next-gen consoles don't have some kind of multi-GPU setup, physics will be done by the CPU. That's because the load on the GPU is much more likely to be at 100% by graphics alone, whereas the multicore CPU's prolly have spare time to do physics. Both the 360 and PS3 have a lot of CPU power even today.
Modern GPU's are basically VPU's (vector processor.) A general purpose processor (CPU) can't perform vector functions nearly as efficiently as a VPU can unless you add the hardware for such functions to the CPU itself.
It would be a brain dead idea from an engineering standpoint to delegate physics processing to a general purpose processor however for multitasking reasons, it would be better to set aside a VPU for that, even if it is inferior to the one(s) set aside for graphics.