OK so something occurred to me. I was originally using this machine for gaming so the display was coming from the 1080. I have now gone into bios, activated the onboard graphics and I'm using that for display, so now all the GPUs are just running cryptodredge and the 1st GPU isn't trying to mine and provide display simultaneously.
I hope this may solve my reboot problems but I will let everyone know. Rookie mistake maybe? I know that when I used to mine ETH I always had onboard video disabled and used the 1st GPU for display and mining but I don't remember the rules for Nvidia and custom versions of ccminer like this one.
historically CD consumes more power than others miners I have used for same algo and same overclock settings.
Yes you don't need too high core for mining CN on Nvidia. The bottleneck of memory hits way before you hit the core so yea as high as the memory OC can take.
Typically 55-60% power is enough for most cards on CN.
ETH-pill gives a boost to GDDR5X cards in CN.