Undervolting Nvidia is not possible at the moment on Linux, for overclocking green with envy should work like the other poster said. Be sure to read up on setting Coolbits to unlock overclocking for Nvidia: https://wiki.archlinux.org/title/NVIDIA/Tips_and_tricks#Enabling_overclocking
Yeesh lmfao’ing in every post, maybe book a visit with a proctologist.