@peroxidechicken
It's not just the CPU that benefits from faster memory. The whole systems benefits from using memory that is faster than what the cpu can handle when it is operating at maximum speed.
Example:
If the memory would operate at the same speed as the CPU and a DMA transfer from a PCI/AGP card comes in to the picture when the cpu is using memory then there will be a severe speed penalty for both of them.
If the memory would operate at a higher speed then the penalty would be decreased.
So "can the G4 actually use memory at that speed?" is a bit misleading question. It's not just about the CPU, it's the system as a whole. The North gate is the central station for handling memory requests on a modern system. And the faster memory it can handle the faster it can share the memory resources between the different parts in the system.
/Björn
