Since so much former chipset functionality now resides on the CPU die, and since there are only a handful of third-party peripheral controllers out there, we rarely see meaningful performance differences between motherboards these days. That said, we still test system performance with different motherboards, if for no other reason than to ensure everything is functioning correctly.
When it comes to testing motherboard performance, we've usually gathered benchmark results using the CPU's peak stock memory multipliers. Since DDR4 is so new, however, and Skylake's 2133MHz maximum stock DDR4 speed is so conservative, we've continued what we started with our X99 reviews and tested our Z170 boards with the memory clocked at the highest speed we can attain while keeping the CPU at its stock clocks.
With no other Z170 boards on hand for comparison, we decided to test against the Z97-P that I reviewed earlier this year. Rather than take the results straight from that review, though, we got some fresh numbers for the board with a Core i7-4790K. To make things interesting, we ran tests with the Z97-P's DDR3 memory clocked at 2400 MT/s. The DDR4 DIMMs in our Z170-A were running at 3000 MT/s. This hardly makes for an apples-to-apples comparison, but the results are interesting nonetheless.
Of the above results, the 7-Zip Decompression test shows us something unexpected. There, we see the Devil's Canyon Core i7-4790K leading the Skylake Core i7-6700K by 6%. This result is repeatable, and the trend corresponds to what Scott saw in his Core i7-6700K review. In the rest of the tests, Skylake matches or beats Haswell, as we would
expect hope for Intel's most recent "tock."
When it comes to boot times, the Z97-P leads the Z170-A by a margin of just over eight seconds. It's worth pointing out that the Fast Boot setting on our Z170-A didn't seem to have any effect on the time it took to go from power-on to the Windows 8.1 desktop. We're looking into this behavior with Asus, and we'll update the review with our findings when we have them. In the meantime, modern systems have perfectly functional sleep and hibernate modes that can mitigate these boot times.
We have more Z170 motherboard reviews planned, so we'll be able to assess the Z170-A's performance against its true competitors soon. Don't expect any big revelations, though. Motherboards typically have a negligible performance impact when all other system components are the same.
Unlike performance results, one's choice of motherboard can have a notable impact on power consumption. We measured total system power draw (sans monitor and speakers) at the wall socket with our test system idling for a period of five minutes in the Windows desktop and then under a full load combining Cinebench rendering with the Unigine Valley demo.
Here we see Skylake and the Z170 platform flexing its muscles rather efficiently. The Z170-A has an advantage in idle power consumption, where it consumes 6W less than the Haswell-based system, and also under load, where the gap grows to 25W. It's interesting to note that enabling Asus' EPU power-saving feature produces power savings of a single watt, at most.
The following page is loaded with detailed motherboard specifications, system configurations, and test procedures. If you're thinking of jumping straight to the conclusion, know that you'll be missing out on important details like how many cup holders and fan headers the motherboard has. Not to mention two more pictures!