small overclock

To go higher, and maintain stability, you're probably going to need to push more FSB and core voltage. Be very sure to understand the specs on that CPU before adjusting those values. From everything I have seen, for that generation of chip, on that series of motherboard 3.33 GHz is a pretty high speed on air- especially with a CPU heatsink with only a 92mm fan. Higher clocks are possible, but not common. I've read the posts talking about 3.6GHz Kentsfield on air across many overclocking forums too, and then the dozens of posts asking how the hell that person managed that. This is even more so on the 680i, a motherboard that has never been particularly strong at overclocking quads. Look carefully in the EVGA forums at system specs in sigs, and you'll see no small number of people with overclocks very close to yours, or in most cases, lower when air cooling a Kentsfield processor on a 680i.

 

I'm trying to think of anything that a QX6850 running at 3.33GHz can't do, and I am drawing a blank. Unless you're gaming on a 17" monitor, you're not going to get more performance while gaming. That's the truth. If you're runnning your games on a 24" monitor or larger, even if you don't enable AA, the process is limited by your GPU, not your CPU. Enabling any AA at all on a 22" screen will put you in a similiar position. People talking about being "CPU bound" in tests like 3DMark, are talking about running that at default resolutions. 1024x768? It is no surprise it's CPU bound at that kind of resolution. Use a paid version of the program, and push the resolutions to something that makes any sort of sense, and you will very quickly see that the application quickly becomes GPU bound, not CPU limited. Lower your OC by changing nothing except that multiplier and see what happens to your framerates at 3 GHz. Don't just take my word for this, test it. Run FRAPS and watch the min framerates during actual gameplay. If you find that there is a dramatic improvement for the games you play between 3GHz and 3.3 Ghz, maybe you should try to improve that CPU clock. If there is no change, you are not going to see any improvement in pushing your CPU to a faster speed. 

 

Finally, you paid for lifetime support. If you really want to try for a faster clock, call DSO and ask if they can help you with it. Get some expert help involved. They have taken a little bit of a pounding on their OC practices lately, but most overclockers deal with Intel boards and refuse to even look at Nvidia chipsets. That's great if all you are after is CPU speed, but if you want the performance SLI brings, you have to deal with an Nforce based board. DSO has OC'd many thousands of systems with Nvidia motherboards. You're not going to find that level of experience with your setup easily. Make use of it.