I recently purchased a new Gigabyte Z170X Gaming 3-EU+i7-6700k.
So, I decided to check out the Vcore of my CPu and to my surprise , even on stock its pushing 1.3 volts because it's set on AUTO.
However, I'm unable to change the Vcore, because the only option available is AUTO, no manual is selectable, this goes for a lot of functions.

My Boards Bios is F20, I wanted to revert it back to F6 but that's not possible as stated by Gigabyte themselves on the Bios Download page.
Is there anything I can still do, or is there a trick to reverting back to the older bios version?