The features of the four motherboards are very similar, so down below you can find all important specifications at a glance.
|SATA||M.2||I/O USB2/3||USB3.1||Network||Fan (PWM)||Phases|
|ASRock Z170 Extreme6||8||1||6 (0 / 6)||1A / 1C||Intel I219V||6 (1)||12|
|ASUS Maximus VIII Ranger||6||1||6 (4 / 2)||1A / 1C||Intel I219V||7 (7)||10|
|Gigabyte Z170X-Gaming 5||6||2||5 (2 / 3)||1A / 1C||Killer E22011||5 (1)||12|
|MSI Z170A Gaming M5||6||2||6 (2 / 4)||1A / 1C||Killer E2400||5 (1)||12|
1 The Gaming 5 also features an extra Intel I219V network controller.
The ASRock Z170 Extreme6 has the advantage of having only USB ports on the I/O panel with USB 3.0 speeds or higher. It also features two extra SATA600 ports. Lastly the Maximus VIII Ranger and the Extreme6 are the only motherboards to feature on-board buttons for power, reset and Clear CMOS. The cons are the high power consumption (relative to other boards in this test) and the weaker sound implementation.
Overall the ASUS Maximus VIII Ranger is a good motherboard. The sound quality is the best of all the boards in this test, basic overclocking options are available, such as on-board buttons for power,reset and clear CMOS, and all fan headers support PWM. The USB 3.1 performance is also the best in this test. The only downside to this board is the smaller number of USB 3.0 ports on the I/O panel, the Ranger only has two, which is less than the other boards in this test.
The Gigabyte Z170X-Gaming 5 also features an excellent sound implementation and is also one of the more power efficient boards in this test. You'll also get an extra M.2 slot and an extra network controller, as far as you find this to be useful. We're not able to test the Intel Alpine Ridge USB 3.1 controller yet, but it promises better performance than the controllers of the other motherboards.
The MSI Z170A Gaming M5 is the most power efficient motherboard we've ever tested and is the only motherboard in this test to feature voltage measure points. It also features an extra M.2 slot. On the other hand we saw the worst USB 3.1 performance of the motherboards in this test. C-states can't be the only culprit in this case, since this model performs even worse than cheaper motherboards from MSI themselves.
The right choice strongly depends on personal preference and what you need. In general the Maximus VII ranger offers the best combination of features, but this motherboard also has a weakness: the limited number of fast USB ports on the I/O panel. None of these motherboards can be labeled as bad. In this extensive comparison table you can see the exact differences once again if you so desire.