Hmmmm, temps.
I just found a bug in the latest Nvidia drivers (actually, seems to be the last latest 3 I downloaded, which seem to be all the 10 series drivers, 1080 1070), where it isnt ramping up the card, its staying in low power mode, also it is not detecting some full screen games.

Try setting this:
Nvidia Control Panel
Manage 3d settings
Power Management Mode
And set it to:
Prefer Maximum Performance

This will make the card stay in both full memory/gpu mode, and will also set the PCI-E mode to the highest (give all the power it needs).
Beware that this will not use turbo mode, and that running the card at full power all the time will shorten the life of the card and fan, but until Nvidia fixes the bug, everyone is kinda screwed. I know you cant roll back to early drivers like I can to fix the issue, so for now that is the only fix.