How to play Minecraft fullscreen borderless

I recently started playing Minecraft again (Thanks, Etho, now I spend too much time on Minecraft again … ).

When I play any game, I tend to play with the game on one screen, and other stuff on my second screen. These days, I mostly log into my Windows 7 desktop and in order to be able to interact easily with my second screen, I tend to put my games in fullscreen borderless (so that the mouse is not locked to the game window). If I can’t put the game in fullscreen borderless, I need to ALT-Tab, which minimizes the game and is annoying.

When looking quickly, Minecraft does not seem to support fullscreen borderless mode. There is a mod here, but adding a random mod to a pre-built pack can be hard in some cases. Then I found a really simple post here. Basically, it explains that Minecraft already supports borderless mode. You simply need to add the following to your Minecraft command line:
-Dorg.lwjgl.opengl.Window.undecorated=true

I won’t go┬áinto how to add the command line to your launcher since there are so many launchers around. Also, make sure you keep the rest of your arguments (for maximum memory, garbage collection and such).

Once you are setup correctly and the game is running, you can then use ALT-UP to go into fullscreen mode.

Sadly, performance tank really badly on my setup here. I’ll have to investigate this before being able to use borderless mode with Minecraft correctly.

Have you guys tried? Do you have any hints on possible performance issues?

Thanks for reading!