Overclocking
Like many of the thousand-dollar, high-end processors of late, the Core 2 Extreme X6800 has an unlocked multiplier, so overclocking this beast is simply a matter of turning up that value in the BIOS—even on an Intel motherboard. With very little effort, I had the X6800 running at 3.46GHz on a 1066MHz bus. This was with air cooling—a Zalman CNPS9500 LED. That's very good air cooling, yes, but nothing terribly exotic.

I had to raise the voltage from the stock 1.2V to 1.375V in order to get it to be completely stable, but at those settings, the CPU ran a pair of Prime95 torture tests for a good while without throwing any errors. With the cooler fan running at its top speed, the CPU leveled out at about 70°C while running those tests.

I tried to coax the X6800 into running at the next multiplier up the ladder, for a top speed of 3.73GHz, but it wouldn't quite go there. Even with 1.45V flowing into it, the X6800 would POST but wouldn't boot into Windows. I suspect this CPU could go well past 3.46GHz with some bus overclocking, but I haven't tried it yet. Even at "only" 3.46GHz, performance was astounding.

This architecture has more headroom than a Ford Excursion. Performance scales up very well with clock speed, too. In fact, these scores may give us some insight into why Intel chose not to move to a 1333MHz front-side bus for the Core 2: the 1066MHz bus just doesn't look like a serious performance bottleneck.