Why would I want to run my 5090 at these voltages anyway?
I have mine underclocked so it runs with 970 instead of the 1055 it usually runs at. Let voltage - less power consumption and even higher FPS (at least 4fps gain in most cases)
Don't run you default clock speed on the default voltage. That doesn't make any sense. It doesn't help your system, your power, or your fps.

As perfectly demonstrated here, as soon as something is wrong and you can't reach the voltage that is meant to run your max clock speed you will lose performance.