Graphical Settings
This should be somewhat obvious but I may as well make a guide on it regardless.
The general concensous should be to turn everything to lowest apart from textures, resolution and anistropic filtering, if you can't get a good framerate after doing that then you SERIOUSLY need to upgrade your rig.
The majority of the time this will give the best possible framerate/visibility but there can be odd exceptions.
Settings to always use:
Resolution: Use a native resolution if possible, If you can't run it smoothly then you really need to upgrade.
Textures: Set to highest to prevent blurry reticules/scopes on some games unless you have low VRAM.
Anistropic Filtering: Set it to highest since it has almost no performance impact.
Field of View: Normally you will want to set this between 90 and 115. Higher FOV can make aiming harder but improves your situational awareness.
Preload Shaders: Can help prevent microstutter mid game.
Settings you should probably disable for a competitive advantage:
Model Detail: Adjusts polygon count, normally not worth lowering.
Shader Detail: Effects lighting and shading effects, medium performance impact.
Anti Aliasing: Smooths out jagged edges but with a VERY high performance hit.
FXAA: A cheap version of Anti-Aliasing that tends to make the game look blurry.
Shadows: I'm sure you know what a shadow is. Normally quite a heavy performance setting.
Ambient Occlusion: Adds darkness to crevaces and around objects but reduces performance a fair bit.
Bloom: Normally makes everything look burnt out and overbright.
Water Detail: Reflections can have a heavy impact on performance but they do look good.
Settings to always disable:
HDR: Messes with your eyes and never really looks good.
Motion Blur: Destroys your framerate and makes it harder to see.
Depth of Field: Similar to motion blur.
Physx: It can be kinda cool but my god does it destroy your framerate.
V-Sync: Sometimes known as, "Sync every frame". It caps your framerate to a multiple of 15 and adds several extra frames of input lag, to try to prevent screentearing.
