Originally Posted by TwoCables
With genuine thanks to this thread, I just lowered my VCCIO from 1.15625V to a manual setting of 1.00625 because my DRAM Voltage is 1.50V (to make sure that it's always within 0.50V of the DRAM Voltage).
From my understanding of it, VCCIO is your IMC's voltage. It's safe up to 1.20v. Having more than needed VCCIO isn't necessarily going to hurt anything at all. It might also help increase stability at a high overclock.
But that's why my VCCIO is at 1.20v. My VDIMM is at 1.70v to get DDR3-1950 out of my sticks. Can't seem to push them any harder. That's why I just bought 16GB of 1600 RAM at 7-8-7-21, 1.65v. I'm hoping they'll be able to push a little harder.
Keep in mind though, I have no troubles at all pushing my limits to the maximum I can go safely. I have warranty for a reason, and I will more than likely upgrade before the warranty expires anyway, and sell my parts for dirt cheap. As such, I definitely don't RECOMMEND pushing VCCIO to 1.20v and VDIMM to 1.70v. But its perfectly fine to run 1.15v / 1.65v respectively. Going more than that, you're pushing to the limits like I do.