Setting voltage on 6600K

I have the Gigabyte Z170X Gaming 7 with NH-D15 cooler.

I'm able to run 4.5 Ghz with Prime95 at 1.225V. The temps stay reasonable, but the voltage is constant at idle even with manual voltage. When I use the stock voltage, the voltage bumps up to 1.272V during stressful programs like Prime95, and the temps shoot up to 74-75C, which is much higher than I would like, and that kind of voltage is simply unnecessary. Also, the temps are preventing me from trying to overclock more. To get variable voltage I tried adjusting DVID, but I if I set DVID to just -0.010, I can't boot. This is annoying because I am forced to allow a much higher voltage and much higher temps than is necessary. Anyone else encounter this problem? Should I just use a constant voltage, or just deal with the higher temps and voltage? Thanks.

Edit: Some grammer, and I didn't run Prime95 for very long. I know how stressful it is, so I didn't need to push it for too long. Also, some were surprised to hear that I was running 4.5 Ghz on 1.225V. The voltage was actually not 1.225V. Even though I have LLC on high, the voltage dropped during Prime95 to 1.212V. The temps also stayed very low. PROOF:http://imgur.com/ikRTqES
More Proof: http://valid.x86.fr/izv4me