Well, it depends on what you are doing. Rendering, obviously, is pure processor. However, start adding several figures, textures, clothing items, etc, to your scene and it gets WAY more RAM intensive. I've got 1.7 gigs of RAM on a Dual Athlon XP, and it was the RAM increase that made the difference for me, not the processor upgrades. In the end, every little bit helps. A better machine is a better machine. No app out there is written to use only one component. All the 1's and 0's have to make their way from the hard drive to your eyes regardless of what app is manipulating them, so they're going to travel through the bus in it's entirety, anyways.