Undervolting a 3080
We've seen this work very well on recent Ryzen chips, and it also works well on graphics cards. Following the instructions in the link below, I have reduced core temps by about 6-7 degrees, fan speed never exceeds 50% and even the coil whine seems to have been eliminated. I ended up with 825mV at 1800MHz which has so far proved stable in Port Royal, Control (RTX+DLSS) and Battlefield V (RTX). It takes a couple of hours, although most of that is letting the Port Royal stress test run to completion several times.
Follow the guide on bjorn3d.com