I just upgraded to an AMD Athlon 1GHZ from a P2-300MHz and most my renders are now 10x faster. I do not have exact numbers yet but there was a definite speed up. One difference between AMD and P3 is the memory types; P3 uses a 133 MHz SDRAM while the Athlon uses 266 MHz DDRAM. The DDRAM has similar specs to the Rambus Memory but for a much cheaper price. I hope this helps, Sam