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).
The power consumption comparison is where MSI Z77A-GD65 really shines. When tested with nominal settings, this mainboard turned out to be the most energy-efficient mainboard in idle mode. Moreover, its power consumption could have been even lower if all Intel processor power-saving technologies had been enabled by default. Micro-Star has every right to be proud of their “Military Class III” components: their use does pay off big time, as we have just seen. Under higher load the board hands over the lead to a more energy-efficient ASRock Z77 Extreme4, but still remains among the best.
During overclocking MSI Z77A-GD65 is the winner in all tests, under any type of load as well as in idle mode, but this advantage is not really definitive any more. All other mainboards consume more power, but they also overclocked our test CPU to higher clock speeds and therefore have higher performance. It would also be unfair to compare MSI Z77A-GD65 against Gigabyte’s board even though they both reached the same overclocking frequency for the CPU. The gaming Gigabyte board has extensive functionality in multi-card graphics configurations by integrating an additional PCI Express hub, though it has to put up with higher power consumption because of that.
In other words, other mainboards also allow overclocking processors without increasing their Vcore, which will obviously lower their power consumption. However, it doesn’t work the other way around for MSI mainboards: they do not allow overclocking processors by raising their core voltage without losing any of the processor power-saving technologies. This nullifies the value of MSI Z77A-GD65 energy-efficiency during overclocking. No wonder this board consumes less than any other one, since we had to avoid increasing the processor Vcore. That is why our overclocking result is lower on MSI Z77A-GD65 than it is on any other of the tested mainboards.