>>105713240
GPU performance doesn't scale very well past 1.1V for Ada and probably also Blackwell GPUs.
Earlier 4090 & 4080 cards were specced to draw 1.1V max, I'm assuming NVIDIA reduced it to 1.075V to make the card run a bit safer.
The Ada chip also has strange power characteristics past 1.125V, it asks for significantly more power after that.
I think Der Bauer's 5090 OC showed similar behavior when he tested a volt mod.

Maybe NVIDIA could've let board partners design OC cards with a higher power limit.
These cards would be obscenely overpriced though.

>>105674266
It's a form of protection to discourage people from volt-modding the card.
RTX 4090's power draw also behaves strangely past 1.1V (nearly 50W increase going from 1100 to 1125mV)

>>105617015
Go to the fan tab in the options and check whether your custom fan curve is disabled.
Worst case, just uninstall Afterburner.

You shouldn't unlock voltage control or voltage monitoring in Afterburner in the General tab.
1.1V is enough for a daily OC, the chip runs extremely power inefficiently past that.