Low GPU and CPU usage

GPU usage is around 30% and cpu on all cores and threads around 50%, frames keep dropping below 100.
System specs:
GTX 1070 ti
I7 4770
16gb 1600Mhz ddr3 ram (2*8gb dual channel)
Nvidia 3d settings are on prefer max power, and Windows 10 settings are on max power too.
Even though im playing on the lowest settings 1080p frames keep dropping below 100 fps in fights, dont know what to do anymore.
Graphic drivers are up to date, used ddu to unistall all drivers, and reinstalled the newest ones multiple times.

Does this issue only appear in Overwatch?
If not, do you use any overclocking utility? If so, try to reset all settings in it. Also, what is tour power supply wattage?