I recently picked up an EVGA 1070 SC to replace my dated (very dated) EVGA 560. Out of the box, it will overclock on default settings to 1960Mhz and normally stay in the upper 1800's, mid 1900's when gaming. When I've gone to overclock it, I can reach about 2075Mhz, but it jumps around a lot and normally always drops. Looking at Precision and GPU-Z, it looks like my voltage doesn't stay very consistent. Even with a higher power target (112%), I am not able to remain at 1062mV consistently, normally dropping to the 1050mV (or below) range with quite a bit of fluctuation. Power consumption never gets above 105% according to GPUZ TDP, and is normally in the high 90's under load. vRel and Pwr are pretty much always up on PerfCap reason.
 
So, given I've been out of the overclocking business for awhile (I'm still running a 2500k), I had a few questions.
 
1. Should my voltage be consistent at 1062mV when power target is maxed?
2. Is the fluctuation a symptom of a PSU that's not able to deliver consistent power? (I have a 5 year old Antec HCG-750W). A limitation of the single 8-pin connector?
3. I know when you over clock a CPU, you experience a voltage drop under load - does a similar thing happen on a GPU - thus causing the rapid changes?
4. tl;dr - Are consistent clock changes (up/down) normal for a 1070?
 
Thanks!
 

With the standard fan settings I would max out at 75 C. With manual settings, I was staying under 60.