Dell S2721DGF + RTX 3080 but I have no smoothness in-game, screen tearing, lagging, fix smoothness, input lag? how to fix it?

[b0ne-]

Yo! My monitor is Dell S2721DGF.My monitor refresh rate is 165 hz, my gsync compatible technology is disabled, vsync

is also disabled, the refresh rate is set to 165, all nvidia 3d settings are set to maximum performance (where it is possible).

I have uploaded quite a few pictures about my nvidia settings and my monitor settings.

 

MY MAIN PROBLEM ---> When I start playing doom eternal, everything is okay in the first 30-40 seconds but 

after that 40 second time period the smoothness suddenly disappears, I feel like the game is lagging, I feel like

there is screen tearing I feel like there is no smoothness, I mean it's still smooth and nice but it's not like the smoothness during the first 30-40 seconds.

I know all of this does not make any sense but I am desperate and idk how to fix that.

I have rtx 3080 + 5600x + 16 ram + good airflow in my case,  I get 250+ fps sometimes it even hits 400 I play on 1440p everything on low.

Is the problem in my monitor or in the game (Doom eternal) itself?

 

 

 

[SpaceGhostC2C]

14 minutes ago, b0ne- said:

My monitor refresh rate is 165 hz, my gsync compatible technology is disabled

Enable it.