I've been planning on upgrading my computer, and my new computer would be replacing my old e8400 with a new i5 750 processor.  I was wondering; using Carrara 8 Pro, would I have a significant speed increase in rendering? If so, by roughly what percent?  Does Carrara 8 pro support all four cores in the i5 750?  I realize it's not a large upgrade, but I need a new motherboard and the one I want isn't compatible with the 8400.