If you just bought a new computer what are you comparing the difference in speed to? I assume your old computer is slower. If the new computer is the same as old computer then there must be something else.

Try some benchmarking tools to compare the differences (graphics, ram, hdd speed etc).

Memory Speed cannot be compared to CPU speed directly if thats what you are hinting at. There are all sorts of calculations to take into account. Clock multipliers, voltages, bus speeds. Try reading an over-clocking guide to get more of an idea of what I am talking about.