BIOS at default, i5 6600k Voltage going over 1.2V

zumypc

Prominent
Oct 3, 2017
1
0
510
I decided to try out the Fast Tuning 5-way Optimization in AI Suite III that came with my motherboard. I got up to 4.3Ghz @1.25V or something and everything was perfect. Then, I decided to do the Extreme Tuning and got to 4.7Ghz @1.3V. I played CS:GO and PUBG and found that there was stuttering every couple of minutes. I decided to reset my BIOS. I then was getting 3.9Ghz (Intel Turbo) at very inconsistent voltages over 1.3V on load. My BIOS says that my CPU voltage is 1.2V, but is still going over.
Help is very much appreciated!
I'm new to overclocking BTW.

i5 6600k
ASUS Z170 Pro Gaming Motherboard
GTX 960 FTW+ ACX 2.0+
8GB Kingston Technology HyperX FURY 2400MHz DDR4
Cooler Master Hyper 212 EVO 120mm
LSP Ultra 550W ATX PSU