Help with unlocking voltage on a Gigabyte Gaming 6 z170 motherboard

Cyanity

Commendable
Jul 17, 2016
2
0
1,510
The quick and dirty deets:
Gigabyte Gaming 6 Z170 mobo (rev 1.0)
F2 BIOS
cpu: i5 6600k

Hey Tom's Hardware, been reading this forum for a long time but finally decided to make an account for this one. I just recently built an i5-6600k + gigabyte gaming 6 z170 motherboard based system and have had decent success using the pre-built overclocking settings for my CPU. The problem is - I've hit a wall. Gigabyte's preinstalled OC settings haven't been touching voltage and go unstable at 4.5ghz.

I've been tabbing through the BIOS settings and cannot seem to find any way to unlock the manual vcore settings and there doesn't seem to be anything specific written in the manual. Any help is appreciated!