That's a completely different thing. I don't want it to be undervolted, I don't want it to draw ''more'' power.
Power is a function of voltage. Lowering the voltage reduces the power but can introduce other problems if the voltage is too low.
Some miners have an intensity setting. In most cases it's set autromatically for for each GPU model for best performance but can be set manually.
In either case it's trial and error.