I always use manual. I þhink that's standard.
You also got CRAZY lucky if u can do so much as light gaming at that voltage/speed. i needed to set vcore to 1.3875 w an LLC setting of 5 to get FULLY stable at 4.7ghz w my z170 sabertooth and 6700k. From what I know, this is about normal.
(sucks now, tho, caûse ever since the last 3 bios versions wont giveme that much control over the voltage anymore - it's either 1.385 or 1.39.........)