Upgrade to Q9450 or Q9300???

Hello guys

I am thinking of getting a new comp, now i know exactly what components to get except for one thing and that's the CPU. Because i am keeping costs to a minimum I can't decide between the Q9300 which is cheapest or the Q9450. They both are similar apart from the Q9450 having 12MB cache and the Q9300 only has half of that 6MB cache.

-Will the drop in cache make such a big difference?
-Which one shall i get?

"Space has no boundary, that is empirically more certain than any external observation. However, that does not imply that space is infinite" - Bernhard Riemann