What I meant too is dual will not cut the speed in half. Some people think it will but that is not correct and it's been tested time and again. Two computers will half the speed, dual processors will just improve it less than that. Poorly thought out scenes don't mater how good they look will probably kill your computer. Those quality sliders should be displayed as graphs so you could see how much extra time it will take for almost no improvement on quality. It's exponential growth, not linear.