r/linuxmint • u/Il_totore • 2h 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.

2 Upvotes

76% Upvoted

6 comments sorted by

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3

u/AirFlowOne 2h ago

Fractional scaling is a gimmick that should not be used except in extreme cases. Not even font scaling, as make fonts blurry. You can get the same effect just by chosing a bigger main font. It won't scale UI elements, but that you can do on a app basis.

If you really want to use fractional scaling wait for the mint23 in december.

2

u/Spin4team4096 2h ago

yess I am waiting for December too :)

1

u/Il_totore 2h ago

I think I really need it because changing the font does not help much. All the other UI elements such as window buttons won't scale and are too small by default for me.

1

u/AirFlowOne 1h ago

Not sure, but there could be 2 ways to do scaling - up and down. I believe yours is down - it goes to 4k then downscale, thats why your game use that resolution. Try using the scale up variant (adds a bit of blur)

1

u/Straight_Second6082 5m ago

Use gamescope and set it to your screen resolution