Plusthinking Iq :
sometimes nvidia drivers can cause this, re install drivers, no beta...
also check gpu-z,
It could only be NVidia drivers if theres gaming involved. At idle, drivers shouldn't have anything to do with it. It'd be gpu monitoring/overclocking software, which evga would be precision x, unless your running like msi afterburner or amd something or other.
It could be geoforce experience, like a setting for performance/quality or such, but at idle, with no programs open, there shouldn't be a single driver controlled software program running.
But other than just idle with no programs running, you'd be more than likely 100% right, im not trying to bash at all.