[SOLVED] How to improve input lag and FPS on Windows 10 1803 (April 2018)

[Voiddr]

This is not a question but rather an answer for those who want to know how to fix a problem with fullscreen performance on Windows 10 1803 (April 2018).

The latest version of Windows 10 introduced a thing called "fullscreen optimizations" enabled by default. This actually runs games like Rust in borderless fullscreen mode even if you force them to run as native/exclusive fullscreen mode. For some games it may work, but for others degrades performance, dropping FPS and increasing lag on input devices.

I wasted a few hours to find out the root cause and get a working solution.

Rust was made on Unity and to avoid crashes on earlier versions of Windows it runs in borderless mode. You can set the launch option '-window-mode exclusive' on Steam to (supposedly) force it run in native/exclusive mode, but it doesn't work because that Windows 10 "thing" is enforcing its fullscreen optimization and therefore running in borderless... There used to be a global option in Windows Settings at 'System->Display->Advanced graphics settings' but its gone. So the easiest way to fix it is to find out Rust.exe -> Properties -> Compatibility tab and check 'Disable fullscreen optimizations'.

tl;dr

Steam app -> Library -> Rust -> Properties -> Set launch options: "-window-mode exclusive" (without quotes)
Steam folder\steamapps\common\Rust\Rust.exe -> Properties -> Compatibility tab -> check 'Disable fullscreen optimizations'.

Hope this will improve your Rust and PvP experience!

All the best,
Ruben P.