That depends on where you are now with your temps. At 60C +-5 doesn't matter much. At 80C, it matters quite a lot. It likely enables you go up another tenth on the clock -- possibly two depending upon CPU. Those are peak values. I find the average CPU temp can be as much 10C lower on water versus large air towers for normal activities. The trade-off is radiator fans will have a coarser sound profile than a large air tower. So if you are a purist and like things very quiet, you may be happier on air. it's not really the voltage, but the actual end temperature that will matter. 1.20 might be conservative. 1.25 might be a better target. I was able to run a Dark Rock Pro 3 on a 5820K@1.25v in the heat of summer and max out at 75C on the typical frying pan #3 core. The 5960 is more watts, so perhaps 1.20 is reasonable after all.
Edited by XTAC - 6/6/16 at 6:27pm