My last system was a dual Pentium 3 850 mhz machine. I had 100 mhz ram in it initially. when I upgraded to 133 mhz ram, I saw a HUGE difference not only in render speed, but all applications in general. Ram speed does make a big difference. I'm using a P4 2.4 ghz with 266 mhz ram, and I am wishing I had waited for the new 333 mhz ram.