We normally do not measure the mainboards power consumption. But we will make an exception for Asus P5E, since not every mainboard out there can boast something like that on the package: “ASUS Exclusive Energy Processing Unit – 58.6% CPU Power Saving”. This promising statement inspired us to measure the power consumption of similar systems (without the monitor) built on Asus P5E mainboard with EPU and Asus P5E Premium without any special technologies. We performed the measurements in idle mode as well as for fully loaded system. Both platforms featured a Core 2 Extreme QX6850 processor working at its default frequency. Enhanced Intel SpeedStep and AMD Cool'n'Quiet power-saving technologies were activated.
As we see, there is no promised economy here whatsoever. Moreover, the new Asus P5E mainboard consumes a little more power than Asus P5K Premium in case of full CPU utilization. However, we shouldn’t forget that Intel X38 chipset itself boasts about 20W higher power consumption than Intel P35. That is why it would be incorrect to say that the processor voltage regulator on Asus P5E is not more economical than that of the opponent. Despite a more power-hungry chipset, Asus P5E performed as well as mainboards on other chipsets in our test session.