We perform our power consumption measurements with 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 on the PSU itself. In the idle mode we start the computer up and wait until it stops accessing the system drive. The mainboards are sorted in the order of ascending power consumption. The results of the ASUS Gryphon Z87 are colored differently, but it is actually always at the top of the list.
When there is no load, the micro-ATX mainboard from ASUS beats the traditionally economical MSI. The other two products are somewhat disappointing. Judging by our earlier tests of full-size LGA1150 mainboards, the average level is 45 watts whereas these two consume more at their default settings.
For all their downsides, Haswell-based CPUs should be given credit for requiring less power in idle mode in comparison with their LGA1155 counterparts. Unfortunately, we can’t see that when the mainboards work at their default settings, so we have an additional test mode called Eco. It means the same default settings but we manually switch all options referring to Intel’s power-saving technologies from Auto to Enabled in the mainboards’ BIOSes.
The results are better now and most of the configurations need much less power. The micro-ATX mainboard from ASUS is still in the lead, followed by the ASUS Maximus VI Hero. The results of the MSI mainboard are almost the same as in the previous test, though. According to our measurements, the power savings amounted to a mere 1 watt but we explained the reason in our previous review. The MSI Z87-GD65 GAMING just doesn’t allow you to enable each and every power-saving feature, which is why it is inferior to the ASUS models which use them all. On the other hand, it is better than the Gigabyte GA-Z87X-OC which doesn’t benefit much from the power-saving modes.
We want to remind you that we install an AMD Radeon HD 7970 graphics card into our test configurations. If we instead used the CPU-integrated graphics core, the overall power draw would be lower than 30 watts. Haswell-based CPUs are indeed very economical when idle, so it is a shame that the mainboards do not ensure this advantage by default. You have to correct some BIOS options for that.
To measure the power draw of our configurations under typical applications, we used the Fritz benchmark. It doesn’t really matter which exactly application you use for that purpose. Any ordinary program that can run on four CPU cores will produce the same or comparable results.
The ASUS Maximus VI Hero doesn’t ensure the standard operation mode for the CPU but increases its clock rate. Therefore, it is inferior to the other mainboards in terms of power consumption.
For power consumption tests under high load we run the LinX utility, which is a graphics shell for Intel’s Linpack test and supports AVX instructions. It is heavier on the CPU than ordinary applications, yet it is just an application nonetheless. It is quite possible that there are some other programs that can be just as heavy. That’s why we stick to using LinX for the purpose of checking the computer out for stability and for measuring its power consumption.
The mainboards from Gigabyte and MSI have a normal power draw of 130 watts or higher whereas the ASUS Maximus VI Hero needs more power due to its nonstandard settings. As for the Gryphon Z87, it differs too much from the other mainboards. As opposed to the ROG series, ASUS's regular and TUF mainboards drop their CPU clock rate at high loads, lowering performance. So it turns out that none of ASUS LGA1150 mainboards can ensure standard system settings by default. That's not what we expect from the leading mainboard manufacturer.
By the way, you have to count in the graphics card’s power draw at high loads to calculate the overall system consumption. We use high CPU loads in our power consumption tests, but if we load the AMD Radeon HD 7970 by running some heavy game, the total power draw will be close to 250 watts at default settings and even higher at overclocking.
Now let’s see how much power the mainboards need in idle mode when overclocked.
We don’t have a special Eco mode here because we always use as many power-saving technologies as possible while overclocking. That’s why the standings are the same as in the Eco mode without overclocking. The mainboards from ASUS and MSI consume the same amount of power, the ASUS products being somewhat more economical due to the MSI’s inability to enable the deepest power-saving modes. The Gigabyte GA-Z87X-OC is the first LGA1150 mainboard we’ve tested which at low loads consumes more power in the overclocked mode than at the default settings. There seem to be certain problems with the power system and power-saving technologies Gigabyte implements in its mainstream and top-end mainboards.
When the overclocked configurations have some work to do, their power consumption is expectedly much higher than at the default settings due to the increased clock rates and voltages. The ASUS and MSI mainboards are comparable in that case whereas the Gigabyte GA-Z87X-OC remains the least economical among them. With its few onboard controllers, the compact micro-ATX model from ASUS wins this test.