Classic British Flight Sim

I see a lot of people using FSX talking about a 3 ghz processor I"m looking at this one
Intel Core 2 Extreme QX6850 Quad Core Processor Kentsfield LGA775 3.0GHZ 1333FSB 8MB Retail W/ HSF, from what I've been reading this processor
is supposed to be the "bees knee"...........at the moment of course.

My question is....is there that much of a difference between the above and say the Q6700 2.66ghz in performance for FSX. As I know a flt sim is CPU based rather than the vid card.

Thanks in advance for any help.

I'm running the 2.66 one with 4 GB of RAM with no problems, however, I know some folk say they can see a difference with the faster chip... question is, is the 3GHz chip £250 faster... I don't think so, but on the other hand, always buy the best you can afford, that way it will be longer before it need replaced

Sound advice XR thanks...