Read the June 2008 issue of Maximum PC's Deathmatch: Q6600 vs. Q9300.
Using a 790i ultra the Q9300 was the better overclocker able to hit 3.5 on air "without a sweat" according to the article ( read it and weep kids dont argue with me) and the better overall performer.
Link plz, I can't find it. Oh, and theres more to overclocking than temperature of the cpu. No doubt at any speed the q9300 would run cooler, but the chipsets starts becoming an issue at that fsb. And the voltage? Putting 1.4 volts through a q6600 is safe, yet that voltage through a q9300 would quickly degrade the processor due to its 45nm architecture. In short, yes, with a good motherboard it is easier to achieve higher speeds with the q9300, but for the average user using it in an everyday comp for 2-3 years, the q6600 is the better choice.
here are the prices i dont like buying stuff online since i am never home when the stuff comes so i need to buy it locally ok the q9600 is 229 with retail cpu
the 9300 is 259 with a cheap ecs mobo and no heat sink.o btw will a cooler from a e6300 work with either of these cpus?
My new system is running a Q6600 and hit 3Ghz easily with a minor Voltage bump, I've not experimented any further yet though. If the Q6600 didn't overclock well then I would of Bought the E8400. The Q9300 is a newer 45nm chip, but it costs more while not offering enough over the Q6600 to Justify the price. The Q9450 is the best 45nm choice, but still too expensive...the Bang for Buck goes with the Q6600 by a mile.
The Q6600 is great if you planning to overclock far, it will run warmer than the q9300. The Q9300 is kinda handicapped for overclocking with the low multi and half the cache. The Q9450 would be good if you can get it, or better yet the Q9550 if you have the cash.