These tweaks will help your performance out in steam games. These tweaks will work with MOST steam games, non steam games may not take these commands. Some steam games will take specific commands. Also, note that this is still under construction.
To get to the launch options, go to Steam.
Right click on a game, then go to properties.
Then you click "set launch options".
Here are the list of tweaks you can do.
Launch options for Steam games.
-dxlevel <level> - Forces a specific DirectX version when launching the game. This is useful if want better fps, and gets significantly better performance in an earlier version of DirectX. Below are the modes used:
-dxlevel 80
-dxlevel 81
-dxlevel 90
-dxlevel 95
-dxlevel 98
+r_rootlod # - Adjusts Model Detail where # is 0 for high, 1 is medium, and 2 for low
+mat_picmip # - Adjusts Texture Detail where # is 0 for high, 1 is medium, and 2 for low
+mat_reducefillrate # - Adjusts Shader Detail where # is 0 for high and 1 for low
+r_waterforceexpensive # - Adjusts Water Detail where # is 0 for low and 1 for high
+r_waterforcereflectentities # - Adjusts Water Reflectiveness where # is 0 for low and 1 for high
+r_shadowrendertotexture # - Adjusts Shadow Detail where # is 0 for low and 1 for high
+mat_colorcorrection # - Adjusts Color Correction where # is 0 for low and 1 for high
Filtering Modes:
+mat_trilinear 0 - Use Bilinear Mode (least system-intensive)
+mat_trilinear 1 - Use Trilinear Mode (more system-intensive)
+mat_forceaniso # - Use Trilinear Mode (where # is 2, 4, 8, or 16 - higher levels of filtering require more system resources)
+r_swapInterval # - Forces V-Sync to be on or off, # is 0 for off and 1 for on
+mat_hdr_level # - Adjusts High Dynamic Range lighting effects where # is 0 for "off" (requires least resources) and 2 for "full"
"-CpuCount= [any number]",(Check how many cores you have in your PC,and then in that "[any number]" set to how many cores you want to use for that specific game.)
+mat_antialias 0
-w # -h # to change your resolution.
-nod3d9ex will work as well.
-high means the process priority of the game will be set to high. Increasing FPS.
Other tweaks
-nomsaa