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’s power consumption grows up depending on the number of active execution threads in LinX (both at the default and overclocked system settings). The mainboards are sorted in alphabetical order on the diagrams.
We often point out that on many mainboards certain power-saving technologies are disabled by default. This time we decided to illustrate our discontent with this issue with numbers. We measured the power consumption of test systems in idle mode with default settings and then with all power-saving technologies manually enabled.
On Asus mainboard Cool’n’Quiet and c1E power-saving technologies are disabled that is why it consumes more than others. If we enable them and also enable their proprietary technologies that allow to dynamically change the number of active phases in the processor voltage regulator circuitry, the power consumption drops substantially. The same is true for the MSI board. As for Gigabyte, there is good and bad news. The good news is that all processor power-saving technologies are enabled by default and you don’t need to worry about turning them on manually. The bad news is that you need to install Easy Energy Saver utility in order to be able to use their proprietary power-saving tools, because there is still no option in the BIOS that could allow using them. As a result, we failed to lower the board’s power consumption in idle mode and it became the most energy-hungry of the three, although in the beginning things were completely different.
As for the power consumption of Asus Sabertooth 990FX under load, it doesn’t really stand out in the nominal mode.
During overclocking Asus mainboards consumed much more than MSI, which is quite logical since they allowed higher CPU overclocking and therefore required a significant increase in voltages. Gigabyte mainboard is missing on this diagram for the same reasons as before.