How to increase FPS without lowering graphics?

so i want to know if there is anyway to increase fps without lowering graphics and ya there is another problem and that is when i used a command to lower my graphics (r.screenpercentage 50)then the default settings for changing engine scalability stopped working

Some of the options in project settings under rendering might help you, also look into lodsand instanced meshes, basically if youve got ten of one thing use instances, it vastly improves performane,
Turning off cast shadows on objects will also give you a boost, if youve got a city you could look ibto hlod… I would say the easiest way to increase performance without too much work is the first thing i told you, just have to wait for shaders to compile also try setting material quality level to low, the difference in visual quality is barely noticeable but big performance gains

Not sure but in the game Insurgency:Sandstorm, people say that higher graphics=better fps.