LOSTCIRCUITS

CPU power consumption in [W], lower is better. Considering everything, one has to admit that Intel has done a darn good job with respect to power management of the four cores. A 20% overhead over the equivalent C2D E6700 is almost in the noise.

CPU power consumption in [W], lower is better. The numbers show the maximum number of instances of Prime95 supported by each platform. That is, in the case of a dual core CPU, two instances are running in parallel, in the case of four processors, four instances are running regardless of whether they are logical or physical processors.

CPU power consumption in [W], lower is better. The red bars show the power consumption of the entire processor during a single instance of Prime95 running, two instances on one core per die each, three instances and four instances. Obviously, the power consumption does not scale with the workload, that is two instances of Prime95 do not double the power consumption of a single instance. However, this is to be expected since there are still basic Windows funtions running that we already showed to consume approximately 25W. Moreover, the OS overhead needs to be multiplied by 10/6 since the multiplier changes under load from a 6 x to a 10 x value and consequently, the power consumption increases proportionally. In addition, the core voltage increases slightly which causes another increase in power consumption. If those numbers are factored in and subtracted from the measured values as the "adjusted Windows XP overhead", the scaling does actually look quite good as shown in the purple bars. Whatever is off may be a systematic error.