Overclocking the QX6850

Are you joking? That processor has an unlocked multiplyer, making it crazy easy to overclock. That being said, with good cooling and a go q6600, you should be all set. No need to spend $700.00 more for a couple hundred more mhz cpu bandwidth.

Some people are getting 3.6 on high end air with a q6600 go stepping chip. However they are prob. lapping the cpu and heatsink. A more realistic goal is 3.2 to 3.4. Anywhere from 3.2 to 3.6, maybe alittle more on water (perhaps 3.7 to 3.8 if you get lucky) Now I don't have the exteme chip, but I'm going to say on water, ( Good water, not some hundred dollar setup) you might be able to push the high three ghz, low fours. It just doesn't seem worth it for an extra few hundred mhz, but thats just me. On a side note, what will you use this build for?

Honestly... everyone says that so they wont have to upgrade for a while. The trueth is, that by the time one to two years go by, you will be able to buy a chip for $300.00 that will be faster than the qx6850 that your thinking of buying. For example... by the end of 2008 maybe early 2009, the new processors (from intel)with the built in memory controlers will be out. For the price difference between the q6600 and qx6850, you will be able to buy a brand new highend motherboard that supports what ever the new processors are, the processor, and prob. even upgrade your ram. Always buy mainstream and upgrade more often. You will be better off in the long run for the same money. On a side note... the amd X2's will run crysis with a good video card. My q6600 stock is more than twice as fast, not even factoring in my overclock.

Your welcome... just make sure you get a "go" stepping and it should overclock like crazy.

No it's the newer revision of the q6600. They have higher thermal tolerances and use slightly less power, resulting in less heat and higher overclocks. Buy it from clubit or another store that can guarantee one.
Also I didn't mention in my other post that the 45 nm core 2's are coming out for the mainstream market soon and you may be better served waiting for them. If you can't wait then a go stepping q6600 will work well.