Check in The ASUS Z170 Thread, first post there is overclocking review
Scroll down till you see Screenshot with adaptive voltage settings, just try to put like 1.2 on additional voltage, or if you overcklocked try 1,25 or whatever you will need to keep it stable on full load 😉 personally I am using 1,25V on 4,5ghz (it comes to about 1,3V on full load
P.S. anyone else getting problems with forum? As I am getting stranger errors which doesn't let to post...
P.P.S. Captain_Jack_Sparrow how you know where is your cpu made? and whats is your cpu batch nr?