Hi gang, I really think that the CPU and BUS speeds are the main things. When I did a test rendering, I check my performance and also monitored my physical memory usage. My 2.0 GHZ CPU was flatlined at 100% while I still had around 100K of RAM left (I have 512K too). There is a way to increase rendering speed, but its not pretty. One is to purchase a coprocessor card ($3000)or use several computers linked in tandem with each other (the ILM Render Farm thing). In the former, the coprocessor takes all the graphics rendering load off the CPU. One can check the computer performance by doing a CNTRL-ALT-Del (once)and click on the performance tab-the graph and other data shows a lot-Plutom Plutom