I'm aware that there's been performance issues for some players with older hardware. I'm looking into solutions for these, but in the meantime here's a few tips that might help:

-Try changing your Anti-Aliasing method first. TSR might be sub-optimal for older GPUs.

-Its recommended you lower your Anti-Aliasing Quality, especially if playing at a higher resolution.

-Lowering Shadow quality from Epic to High can greatly improve FPS, even on later GPUs.

-Test out the effects of the Dynamic Resolution scale setting on performance.

-Having Volumetric fog turned on has been known to sometimes be problematic while live-streaming.

-There's currently a known bug where setting Foliage Quality below medium can make some bushes with collision invisible.

-If you're noticing high hardware temperatures, make sure you have your FPS Limit set correctly. Also try turning on V-Sync.

-The effects of changing Texture quality are very hardware dependent. Lowering it can even harm performance on some machines.