Which software are you using?
I'm currently using MSI Afterburner, I can't seem to get my card to idle on desk and appears to be running at full speed
Geforce Experience - Experimental features enabled (Alt+R to bring up overlay)
I don't usually use that POS, esp not for optimising games, but thought I would try out the new features.
Might be windows or nvidia power settings then, causing it to prefer max performance all the time.