Power consumption is a highly important factor for mini-ITX mainboards because it directly affects how quiet and economical the compact computer will be. A small difference in power consumption may be crucial for compact PCs because it may call for an additional fan or a higher-wattage PSU. Mainboard developers can have a serious effect on the power draw of the assembled PC by designing an efficient CPU voltage regulator.
So, we carried out a special test to check out the power consumption of the Z77-based mini-ITX mainboards using our Corsair AX760i PSU with its monitoring capabilities. The diagrams below show the full consumption of each system (without the monitor) as measured at the PSU’s output. It is the sum total of the power draw of each system component. The PSU’s efficiency is not counted in.
The CPU was running a 64-bit version of the LinX 0.6.4 utility. We enabled C1E, C6, Enhanced Intel SpeedStep and Turbo Boost to correctly measure the systems’ power consumption in idle mode and at low loads. As in the performance tests, we checked the systems out at their default and overclocked settings.
The Zotac Z77-ITX WiFi is highly economical when idle. The other mainboards need more power, especially the ASUS P8Z77-I DELUXE and ASRock Z77E-ITX. The MSI Z77IA-E53 and EVGA Z77 Stinger disable the CPU’s power-saving technologies and thus require even more juice when overclocked.
The single-threaded load evens out the results, yet the Zotac Z77-ITX WiFi is still superior in terms of energy efficiency. The MSI Z77IA-E53 is the only mainboard that can match the leader at the default settings.
At full CPU load the Zotac Z77-ITX WiFi loses its leading position. The ASUS P8Z77-I DELUXE is now the most economical at the default CPU settings, even though the Zotac is quite economical, too. The overclocked Zotac-based system consumes less power than the Gigabyte-based one which has a lower CPU clock rate. By the way, we want to remind you that the EVGA Z77 Stinger is missing in the diagram because that mainboard drops the CPU clock rate to the default level at full load.