the value r_primitives (0, 1 or 2) could cause a decrease to ~2fps, which could be similar to your behaviour. If your "stuttering and freezing" is a just very low fps number, you could try to set it to 1 or 2
Yeah I think I have a really low fps but where can I change that???
Before you start changing randomly:
/seta r_primitives "1" << will set permanently and write to etconfig.cfg
/set r_primitives "1" << will set temporarily and NOT writer to enconfig
/r_primitives "1" << will set tempor....
It's very common for newer graphics cards that the game doesn't auto-detect the correct primitives mode for them.
Try 1 or 2, restart your game afterwards (not sure if /vid_restart only will do the job) and check whether it became better.
some background about r_primitives: afaik it changes the rendering mode of the game. It supports 2, one was formerly designed for radeon cards, one for for geforce. then there was a driver change at the radeons (somewhere between catalyst 13 and 14) which dropped one of the rendering methods. r_primitives=0 means auto detect. If you are in the wrong fps mode, you will have hilariously low fps. I think it just crashed on older machines for running on <0,5fps, but on newer machines it can still run with ~20 (while it could run at 200 in right mode). The auto detecton is just broken for every card that didn't exist on ET's release date - so its a 50:50 chance to be in the right mode or not.