On my system, I have two discrete GPUs - a P400 and an Nvidia 3090. I use the former for Xorg process and have connected my two monitors to it. I use the 3090 for heavier computation work using CUDA_VISIBLE_DEVICES=0 for using the said GPU. Steam, however, only uses the P400 - and therefore I am unable to run any game (Tekken7, War Thunder, Frostpunk) due to lack of memory. I have tried using DRI_PRIME=0 (In launch options) and CUDA_VISIBLE_DEVICES=0 steam, but to no avail. The steam games continue to use the 2GB P400 (which basically means nothing runs). Is there a way I can run the Steam games on the second GPU?
Edit - I do not have a iGPU.