From what I understand inches doesn’t actually matter the pixel number does you have a 4k tv

if you are having trouble hitting the 60 frames I would tell to lower your graphical settings

however the things you are playing are old af which leads me to believe you have other issues… If I were you i’d make sure you plugged into your graphics card on your PC and are using the correct cable I believe dp cables are today’s standard Unfortunately that’s everything ik GL