Equihash h/s increase with only voltage increase?(nvidia)

[whitrzac]

So at first I thought this was just a fluke and a figment of my imagination....

I've had 3 different 980ti cards that I've mined equihash with.

Stock they would do ~430ish. I could OC to get 460ish at stock voltage.
Overvolting the cards would result in the same clock speeds, but actual hash rate would go up about the same percentage as the power usage went up.
My fastest 980ti is currently doing 500-510h/s with a +87mv on the core, clocked at ~1529 and +400 on memory.   


Has anyone else noticed this?