I have no idea why this isn't easier. Maybe i am over thinking it but I've tried everything i know to do and i've tried to search out guides. How the hell do i switch to Preview screen to render from my GPU?

Possibly a deeper question in the same vein. - I am just using the basic models in preview for quick rotoscoping reference for animations. I dont need them to look fancy or anything i just draw over them in photoshop. But when i get 8 9 10 models ive sculpted the system chugs when i move around and do stuff. my compute_0 is 4%ish gpu 21% Cpu 17% but i am getting janky frames like its 2004 WoW and im spinning in a max server Orgrimmar. Its silly as hell on this rig and my system is all 21 or under. I have no fucking clue what I am setting wrong. I played around in the settings but I think at this point the software is too far outside of my understanding or terminology or something, ive been struggling with the hair thing for a bit. I dunno any help is great. thanks in advance