Any tips for better performance?

I have a 1060gb 6GB Nvdia graphics card, with I5-7640X CPU and 16gb ram.
I have to play borderlands on low graphics because it runs extremely badly on higher settings.
I have no programs open in the background and I am running it on borderless window.

On low graphics there is still fps drops in fights, and things like aiming down sights, With the pc specs I have, Aren’t I supposed to have better performance? I had to turn off most graphic options like volumetric fog, and the game still looks fine but honestly still runs badly

Switching from windowed borderless to full screen gave me 3 extra fps in the benchmark (82fps for me)

for me fullscreen seems to make my games laggier, especially when tabbing out to check messages or something. I am just confused on why im lagging with these specs when I never lagged in other graphic internsive games, I honestly think since they switched to ue4 they messed up optimization