ya i know that, but i was wondering if the change in performance is noticible if you go to 3.4 from a 3.0 or 3.2.
The only reason I'd buy a 3.4GHz CPU now is if I had a lot of money in my pockets and nothing to do with it... but even then I'd probably end up saving some money, get a 3.2GHz processor and lose some 1-8% of overall system performance that I'd end up not noticing. All of this based on the current CPU pricing, of course.
A 3GHz P4 is the most expensive I think anyone would want to spend. If you already have an Intel CPU at around 3 GHz, there is little point getting a 3.4GHz one. Wait a while if you have the money to spend on a 3.4GHz P4. Intel will come out with a better CPU with 64-bit extensions like AMD. AMD will surely have something really great by that time. A 3.4GHz P4 is just not worth the money right now.