I have amd gpu (rx 6800 xt), using cachyos gnome playing games between 30 minutes to 2 hours causes my gpu performance way lower like I am losing 60% gpu performance, oddly enough my wattage doesnt decreases, I tried to switch normal kernel and LTS results were same only way to fix it close to pc and reopen couldnt find a solution, could you help me
Welcome to our community.
I have the 7800XT and had 6750XT too previous years playing so far without issue but I use KDE-Plasma with X11 for gaming. If you use Gnome I have to say is responsible for many performance issues in Arch linux. On Ubuntu works fine but not in Arch I have experience it so far.
Also , my suggestion : If you want to have max performance on games, forget Wayland. Is newer and more modern from X11 , but not mature yet , even after all these years. I have experience many crashes daring gaming with Wayland and not even once with X11 . Many like using it , but I saw some fps gain plus better average FPS with X11.
Last , do you use Mesa drivers or the original from AMD (AMDVLK)? The open source drivers from AMD who are already in kernel, is much better than the official ones. Better optimized .
Hope I helped .