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 Intel Core i7-930 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). We performed the test in four modes: idle mode, single-thread load, four-thread and eight-thread load. The mainboards are sorted in alphabetical order on the diagrams.
The mainboards consume about the same amount of power at their default settings irrespective of load. However, the Sabertooth X58 is far more economical when overclocked, which is due to the default voltage on the CPU-integrated memory controller (we had to increase that voltage above the default level on the Gigabyte mainboards to make the memory modules stable at high frequencies). We should keep it in mind that the lower power consumption is achieved at the expense of performance.