Dependencies of Chipset, RAM, cache and other internal CPU constructions, you will get max. 89.5% more out of a C2Q then a C2D, but that is only with programs like 3Dmax, In general, and with programs from this moment you will get like 50-60% more out a C2Q then a C2D. So, let’s say you will get 80% more out of a single cored Core2 and a C2D plus that 50-60% more when you have a C2Q above the C2D. 1.8*(1.5 to1.6) will get you 270 to 288% of a singe cored CPU, so not 400%, not even close but it will be up to 359% with 3Dmax. Don’t even bother with games…