which is faster,core 2 quad or core 2 extreme?

It depends on what you're doing with the PC. If you're running apps that require 4 cores, the quad is going to be faster. Otherwise, the Extreme is generally going to be faster.

The primary difference between the regular Quad and the Extreme variation (Q vs. QX) is that the QX chips don't have a locked multiplier, so if you get into overclocking, you can bump the multi up, in addition to changing your FSB speeds.

You're paying quite a lot for that little premium, however, and people have pushed the standard Q6600 into the 4Ghz range.

Don't waste money that you don't need to. "Bargain" doesn't always mean "crap quality".

core 2 extreme is better

r u mad, core 2 extreme is currently the fastest processor in the world.........
but it also costs a whopping-$1075