Bit-Tech posted an in-depth look at the performance of the Core 2 Duo E6400, E6600, E6700 and Core 2 Extreme X6800

Intel has spent a long time shouting about it's Core 2 Duo processors, and now it is clear why the company has been doing so for such a long time. The architecture is incredibly fast, and based on our preliminary testing, there is plenty of room for the architecture to scale, too. We were able to get our Core 2 Extreme X6800 running quite happily at 3.46GHz.

Conroe E6400, E6600, E6700 and X6800 Review