We performed our power consumption measurements using an Extech Power Analyzer 380803. This device is connected before the PSU and measures the power draw of the entire system (without the monitor), including the power loss that occurs in the PSU itself. In the idle mode we start the system up and wait until it stops accessing the hard disk. Then we use LinX to load the CPU. For a more illustrative picture there are graphs that show how the computer power consumption grows up depending on the number of active execution threads in LinX. The results on the diagrams are sorted in alphabetical order.
However inefficient Elitegroup mainboards may be, we’ve got a new leader in terms of power consumption. It is the Gigabyte GA-Z68X-UD7-B3 mainboard that sets a new record and quite expectedly so since the hot and power-hungry Nvidia NF200 chip adds about 20 watts to its result. The Intel DP67BG remains the most economical product whereas the GA-Z68X-UD4-B3 is the most energy-efficient among the Gigabyte mainboards. This is no surprise, either, because I enabled all of the power-saving features for this model, the ones that did not work by default on the other Gigabyte products.
The Foxconn P67A-S has the lowest power consumption when overclocked because it is the only mainboard that could not increase the CPU voltage. So, its low power draw comes at the expense of performance. The ECS P67H2-A is the most uneconomical mainboard among those that I’ve tested so far, beating the MSI which disables power-saving technologies when overclocked and even beating the Gigabyte GA-Z68X-UD7-B3 with its NVIDIA NF200. On the other hand, the latter mainboard reached a CPU clock rate of 4.7 GHz at a lower voltage than what I had to set to overclock the CPU to 4.8 GHz on the ECS P67H2-A.