Very Good - 73 Watts For Four Cores
To determine the maximum power consumption of our review sample, we stressed all four cores using Prime95, and once again, we were more than surprised by the result. Compared to its direct quad-core predecessor with the Kentsfield core (Conroe), the new Penryn-based CPU with its High-K Metal Gate technology draws 39.25% less power. We measured the power consumption of both processors in the same motherboard, namely the Gigabyte GA-X38-DQ6.
Although the new Penryn now sports an additional 4 MB of L2 Cache, its power consumption of only just under 73 W undercuts that of its predecessor by roughly 47 W.
Even though the number of transistors has increased from 586 million to 820 million, power consumption has dropped by 39%.
Things currently look very bleak for AMD. Its flagship processor, which only features two cores, draws 123.76 watts. Intel's current top model, a quad-core processor, only needs 72.98 watts. Even the AMD platform's lower northbridge power consumption can't help close the 50 W gap.
Looking at these results, an official 4 GHz variant is entirely feasible for next year. A new stepping could allow for a lower core voltage and would thus be easily possible. We're not sure why Intel specifies a TDP of 130 W for the QX9650. In our measurements, the processor and voltage regulation modules together drew much less power, and would have easily fit into the thermal envelope of TDP 95 W.