Everything below was tried with the latest BIOS for the Maximus VI Hero.
I purchased a Maximus VI Hero a while back with 4770k... finished my build and booted it up. Tried to do what JJ stated 4.6 @1.2 boot it up and pray. No go for me. Ended up 4.6 @1.375 volts to boot. 4.6 @ 1.42 volts to run realbench encode.
I had to memory slots go bad so i returned the mobo and got a replacement (I love Microcenter).
This time to boot into 4.6 it took 1.4 volts and 1.44 to run Realbench. This was outrageous. So i bought another 4770k. Tried same thing.
This time 4.6 @1.3 volts... much better! 4.6 @ 1.36v to run Realbench.
However I would ghet several BSOD etc. After weeks of frustration and testing I decided to try another motherboard from another vendor. I will not go into the type of board.
Install, using the JJ way BAM I booted at 4.6 @1.20v. Stable is 1.212. Ran realbench at 4.6 @1.26.
I have heard from others discovering this very same issue and solving it by changing to a non asus mobo.
I really like ASUS but I am surprised by this and concerned. Anyone else have any thoughts?
Intel i7 4770kOC @ 4.6 / 1.25v - Maximus VI Extreme - 16gb Team Xtreem @2400 Gigabyte R9 290x Windforce OC Intel i7 4670kOC @ 4.2 - ASUS Z97i Plus - 8gb Crucial Ballistix@1600 ASUS 660GTX AMD FX8350OC @ 4.8 Ghz Stable - Crosshair V Formula-Z -8gb Crucial Ballistix @1600 ASUS 660GTX
I'm not sure about the 4770k but I can tell you about my 3770k. It needs 1.54 volts for 4.7 Ghz. which I think is high myself. For 4.6 Ghz. it needs 1.48 volts. This is to run the cpu at 100% load with no crashing. I have the 3770k in the maximus v extreme. I'm not complaining about the performance of the cpu but I'm not impressed by how much voltage it needs to keep it stable.