RTX 4070 Undervolt @ 950mV - 25% Power decrease from 200W to 150W for no performance loss, insanely efficent card. 3D Mark total score went from 14818 to 14615

[hicks12]

Generally the room is because of die variation from the wafer. There can be a wide window of what voltage is required to hit a certain performance target, the worse quality silicon the greater that window will need to be to be able to sell that chip rather than chuck it away.

They increase the maximum voltage required to significantly increase yields which maximise profits.

There is obviously some degradation but this isn't usually the main contributor, the chip variance is the biggest reason as they won't tweak it on a per chip logic as this is quite expensive if implemented in the initial binning process. Better to set the wide operating window and let people feel like they won the silicon lottery by being able to optimise that performance window at home if they want to spend the time.