Overclocking
No matter what I tried, I couldn't get our QX6850 stable at 3.66GHz. I started at the stock voltage and stepped up through the settings to 1.4125V, and I ran into math errors in Prime95 or blue screens of death at every step along the way—sometimes one followed by the other. The problem seemed to be the first of the four cores, which is where all of the Prime95 errors happened. That's life with a quad-core Intel processor: you can't overclock past the limits of the slowest core. I was able to get the QX6850 rock-solid stable at 3.5GHz on a 1400MHz bus, as my CPU-Z screenshot proves in legally binding fashion.

Here's what overclocking this puppy to 3.5GHz will get you in terms of performance:

Tasty.