The guys over at Expreview got their hands on a 45nm Intel Wolfdale dual core E8400 clocked at 3.0GHz.
They reviewed the new part and put it up against the Conroe-based E6850. The results are 2 to3 percent better than those of its 65nm predecessor, but the new CPU runs a lot cooler, and under load it draws around 10 percent less power.
When overclocked to 3600MHz, the Wolfdale runs at 46ºC, while the Conroe heats up to 58ºC. On stock clocks, under load, the Wolfdale works at just 33ºC and the Conroe part ends up at 46ºC. Basically, a Wolfdale overclocked to 3.6GHz generates as much heat as a Conroe at 3.0GHz, which sounds impressive.
You can find the full review here.