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 (both at the default and overclocked system settings).
Power consumption is yet another aspect where Gigabyte G1.Sniper 3 and ASRock Z77 Extreme9 mainboards are close, and at the same time very different from the competitors, unfortunately. The additional PCI-E bus hub makes them consume much more power than the others, although the ASRock board does look a little better. Its processor power-saving technologies work correctly right from the beginning, including the dynamic adjustment of the number of active phases in the processor voltage regulator circuitry, while the same function on Gigabyte mainboard doesn’t work. Also, the power consumption may be additionally lowered by enabling the “Power Saving Mode” in the BIOS, which will lower the CPU Vcore by 0.1 V by default (this value may also be adjusted manually).
During overclocking the situation with power consumption changes a little bit. In idle mod and under low operational loads ASRock Z77 Extreme9 catches up with Gigabyte G1.Sniper 3, and under heavy operational loads its power consumption gets even a little higher. At the same time both mainboards remain pretty power-hungry compared to the other testing participants. However, let’s not forget that ASRock mainboard managed to overclock the CPU to higher frequencies and therefore its Vcore was raised more, so the results remain in its absolute favor.