TechReport has an early review on the new Intel QX9650 45nm 3.0 GHz quad-core extreme desktop CPU (due for launch next month) and the power consumption results are shocking. The new QX9650 quad-core based on the latest 45nm HKMG (High K Metal Gate) manufacturing process consumes less power on average than an Intel E6750 2.66GHz dual-core. At idle the QX9650 system draws 160W versus an E6750 at 175W idle. At peak consumption the QX9650 draws 215W versus the E6750 at 214W which is nearly identical. That's shocking when you consider the fact that we're comparing four 3 GHz cores versus two 2.66 GHz cores.
The E6750 is based on "stepping G" which is already the latest and most mature 65nm manufacturing process from Intel and it was already an extremely efficient CPU. The idea that one of the first 45nm CPUs on the planet on one of the earliest production silicon can get these kinds of results is astounding. What's just as astounding is the fact that Intel calls the QX9650 quad-core CPU a 130W TDP part when the Intel E6750 is already a very conservative 65W TDP part. It is noteworthy that the server version of the 3 GHz 45nm quad-core Intel processor is rated at a less conservative 80W TDP which makes perfectly good sense considering it's in the same power envelope of a conservative 65W TDP chip.
This kind of conservative rating ensures extremely high yields because there is so much leeway on chip-to-chip variation but this degree of conservatism seems a bit unusual. Since this is a multiplier-unlocked "extreme" part geared for the overclocking market, I suppose people will jack up the clock enough to crank it up to 130 watts. Speaking of overclocking, TechReport managed to get a stable 3.6 GHz clock speed without any "crazy-insane core voltages" which is very respectable for a quad-core process this early in the process stage.
The chart at the bottom of the power consumption results page which represents a form of performance per watt metric indicates a 49% improvement over the latest 65nm Intel QX6850 quad-core processor and a 2.2 to 1 efficiency advantage over Intel's E6750 dual-core in Cinebench. AMD Athlon X2 dual-core numbers as well as other applications and benchmarks are also compared so I would recommend checking out the entire article.