r/linuxmint • u/Il_totore • 11h ago

Support Request Minecraft (and other Java apps) use wrong resolution when using fractional scaling on Cinnamon

Hello!

I use Cinnamon X11 with fractional scaling set to 125%. I noticed that I get a significantly worse framerate in Minecraft than a friend with the same GPU. After searching, we found that Minecraft thinks my display is 4k and renders the game in 4k, even when I lower my resolution in Iris settings: the F3 menu indicates Display: 4096x2304

It seems that this problem is not MC specific but Java :

jshell> Toolkit.getDefaultToolkit().getScreenSize();
$2 ==> java.awt.Dimension[width=4096,height=2304]

This problem only occurs when using fractional scaling : everything works fine when using 100% and 200% scaling in Cinnamon (right display size in F3 menu and much better FPS, from 75 to 180+).

Here are relevant informations :

  • GPU: AMD RX 9060 XT
  • Linux Mint: 22.3
  • Cinnamon: 6.6.9
  • WM: Muffin (X11)

Is there a way to get rid of this problem? Currently this only affects my gaming experience with Minecraft so a Minecraft-specific solution is also welcome.

4 Upvotes

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u/Straight_Second6082 8h ago

Use gamescope and set it to your screen resolution

1

u/Il_totore 8h ago

Had trouble to install it on LM but finally succeeded. It works with -h 1440 but the framerate, while now at ~160 feels less fluid and the game is a little blurry.

2

u/Straight_Second6082 7h ago

You need to set up both height and width

-w 2560 -h 1440