Performance is not the only practical spec that may be of interest to potential buyers of mainstream CPUs. In many cases their power consumption matters a lot, as it has direct connection not only to the amount of your next power bill. The same parameter sets certain restrictions and criteria when it comes to picking out a system case. Therefore, we decided to add power consumption tests to our performance research.
The graphs below show the full power draw of the computer (without the monitor) measured after the power supply. It is the total of the power consumption of all the system components. The PSU's efficiency is not taken into account. The CPUs are loaded by running the 64-bit LinX 0.6.4 utility. We enabled all the power-saving technologies for a correct measurement of the computer's power draw in idle mode: C1E, AMD Cool'n'Quiet and Enhanced Intel SpeedStep.
There are three groups of CPUs in terms of power consumption in idle mode. The most energy-efficient group includes the whole LGA1156 platform. The second group combines somewhat less efficient CPUs from the LGA775 and Socket AM3 series. The LGA1366 platform has the highest power consumption when idle, which might be expected considering its architectural specifics.
The picture is somewhat different at load even though the LGA1366 processors still consume the most. The dual-core Core 2 Duo and Core i5 processors expectedly need the smallest amount of power. As for the Socket AM3 platform and Phenom II X6 processors, they are similar to the senior quad-core LGA1156 processors in terms of power consumption.