AMD

I finally managed to buy myself a pc, and managed to pick up an RX 6900 XT, a great graphics card that I now have running at 360w. I love the portal series of games, and want to play the rtx remix versions of portal and portal prelude, and judging by my 3dmark Port royal scores (here) I should be able to run it no problemo as I outstrip an RTX 4070. However, I have to drop my resoloution to the lowest possible setting and use both taa balanced and RSR to get a rough 50 fps. I think this is nvidia kneecapping, i'd like to hear you guys' thoughts on it.

P.S for some reason i'm also only getting ~360 fps on cs2 on medium- low settings, is this normal?