CPU speed seems to be the big thing in render time. Amount of RAM seems to have no real effect, unless you don't have enough to hold the entire file in RAM during render, in which case the render is slowed down cos it has to access your HDD (or these are my findings with my PC). As Erlik says, HDD space doesn't seem to have an effect either.

Dreams are just nightmares on prozac...
Digital WasteLanD