Headroom

Headroom is an extra performance mod for Minecraft: Java Edition. It runs next to Sodium and Iris and helps most when shaders are on.

Press Play and you get Minecraft 1.21.11 with Fabric, Sodium, Iris, the MakeUp Ultra Fast shader pack already switched on, and Headroom.

What it does

• Doesn't draw what you can't see. Mobs, chests, signs and banners fully behind solid blocks are skipped and come back the instant any part could be seen. Nothing visible changes.
• Less shadow work. Shader packs draw every mob a second time for shadows. Headroom leaves out the far ones.
• Holds your frame rate. Pick a target (60 FPS to start). When the game drops under it, Headroom steps down through seven quality levels (fewer particles, shorter mob, chest and shader-shadow distance, and at the last levels shorter render distance), then gives quality back when there's room.
• Quiet in the background. Alt-tabbed out of a world, the game idles at 15 FPS.

Keys

• F8 Headroom on/off, so you can compare for yourself
• F9 readout: FPS, target, level, and how much was not drawn
• F10 target: off, 30, 45, 60, 75, 90, 120, 144
• K shaders on/off, O choose a shader pack (Iris)

Measured, not promised

On one PC (RTX 4060, 2560x1080, MakeUp Ultra Fast shaders, VSync off) in a test scene with 171 mobs and 81 chests behind a wall: 230 to 245 FPS with Headroom off, 256 to 332 with it on and no target (one run of six came in lower, at 207), and 287 to 511 with the governor at its lowest level. Runs vary, and a scene with nothing hidden gains nothing from the skipping; the governor is what helps a struggling PC most.

With VSync on (Minecraft's default) the game never shows more than your screen's refresh rate, so on a PC that already holds it you won't see a higher number; Headroom matters when the game falls below your target.

Good to know

• Client-side only. Works in single player and should work on servers (not yet tested on one); it changes nothing for other players.
• Never skipped: players, named, glowing or leashed mobs, anything within 4 blocks, big entities, beacons.
• Every part has its own switch in config/headroom.properties.

Credits

The release includes unmodified copies of Sodium (CaffeineMC), Iris (IrisShaders), MakeUp Ultra Fast (XavierFST), Fabric API and Prism Launcher. Built with AI assistance. Not affiliated with Mojang or Microsoft.