What it does

If you have your FOV slider up 100% of the way then a circle will appear in the sky. Just lower your FOV to about 70% (give or take ~10%) or until the circle goes away. If you didn't touch your FOV slider then you are fine.

A user reported that -nomansky causes the FOV bug to pop up as well. I have yet to verify it but it was worth mentioning anyway.

IF YOU USE THIS REMEMBER TO SHUT VSYNC OFF IN THE GAME SETTINGS!!!!!

This makes it so the game uses all of your CPU cores. If all of your CPU cores are NOT being used after using this launch option then disable it as it may cause more stuttering.It forces the game to use Shader Model 4 instead of the usual Shader Model 5. The game looks and feels almost the same but you get much better performance. The game has a more matte look to it but it is not bad. Best performance boost out of all of these options.Using sm4 forces the game into using DX10 instead of DX11 and this does the same thing. I put it here to make sure it launched correctly. you are not missing out on anything.This disables a lot of the detailed sky features like a lot of clouds and super starry night sky. This minimizes all of those but you still get them. It looks almost the same but it has less of all of it. You still get stars and you still get the sun and moon. This just gets rid of the sparkling stars at night that can blind you.This launches the game in 4gb memory mode. If you have less than 16 gigs of RAM then this is basically a must have for better performance. You are missing out on some effects like the breaking of bushes and leaves go everywhere. Nothing major at all and the game runs better!Launches the game in high priority mode instead of normal mode.This forces Vsync to be off. Vsync is typically used to stop screen tearing when over your monitors refresh rate. If you are getting below 60fps then make sure to leave this in, if you are getting over 60fps then leave it as it can cause screen tearing.