If all other things are equal (HDD speed and config, physical memory, etc..), how much would rendering speed be improved using an Intel quad core vs. a dual core?
on my quad core I regularly have the bottleneck be the USB2 hard drive. If I edit/render on my internal SATA all four cores go ~100%. With the USB2 drive they top out ~80%.
but with my duel core I can do 3d track motion w/o pre-rendering to see how it looks. So it's great for preview!