Overclocking and EFI
We have no complaints regarding MSI's recent EFIs and the Z170A SLI Plus sports a very similar effort to other boards we've seen from the company. It's all clear and well laid out and you get plenty of overclocking settings too, including basic loadline calibration and all the major voltages, plus there's a useful fan control suite too. It's not as flexible as Asus's efforts, but it's handy to have and much easier than fiddling around with figures and percentages as you do on most Gigabyte boards.
It's simple to set a vcore and multiplier for basic overclocks - probably all you'd want to do with this board anyway. However, we also go for broke in our reviews to see the maximum each board can do that's both Prime95 stable and able to run through all of our benchmarks without a hitch. We aimed for 4.8GHz, with the maximum we've seen being 4.9GHz and worst 4.6GHz.
Many of MSI's board have fallen short here and while the Z170A SLI Plus didn't manage 4.8GHz we just about coaxed 4.7GHz out of it with a 1.38V vcore. It's unlikely, then, that this is the best board for maximum overclocks, but if you're aiming for something in the region of 4.4GHz 24/7, you shouldn't have any problems.