noahdunnagan/mcopt

A Minecraft performance mod for Apple Silicon Macs. Since 0.3.0-alpha.1 it draws the world with its own Metal renderer. Very much alpha: expect bugs, and back up your worlds.

• An Apple Silicon Mac on macOS 26 or later
• Java 25 (the official launcher and Prism download it for 26.3; nothing to install)
• Minecraft 26.3 with Fabric Loader 0.19.5 or newer

1. Install Fabric for Minecraft 26.3: https://fabricmc.net/use/installer/ (or in Prism Launcher: new instance, 26.3, loader Fabric).
2. Download the mcopt jar from Releases.
3. Put it in ~/Library/Application Support/minecraft/mods. Create the mods folder if it's missing (Finder: Go > Go to Folder). In Prism: Edit the instance > Mods > Add file.
4. Start Minecraft with the Fabric profile.

Sodium isn't needed anymore: mcopt won't start alongside it, so take Sodium out of that folder if it's there. Fabric API isn't required; keep it if your other mods need it.

To check it's working: press F3 (fn + F3 on a Mac keyboard); the bottom right says Metal 3 (mcopt).

Shows an fps counter in the top-left corner (hidden with F1 or F3; fn + F1 or fn + F3 on a Mac keyboard).

• The perf profile is on by default.
• profile=none in ~/Library/Application Support/minecraft/config/mcopt.properties (in Prism, the instance's minecraft/config folder) turns it off. The first launch writes that file.
• Far terrain is an experimental opt-in: mcopt.lod=true in the same file, for Macs with 10 or more GPU cores.

fps spinning / flying, same test world, 1920x1080, render distance 16, VSync off, at least two runs each:

The mini and Neo cells ran on 6c133ecc, whose only difference from 9865a0a3 is vGroup, which is gated off on those GPUs. The Neo's vanilla and Sodium cells come from the da566d00 run. This build differs from 9865a0a3 only in code that runs when Distant Horizons is installed.

For the most fps: Options > Video Settings, VSync off and Max Framerate Unlimited. The numbers above are with VSync off.

• Mods that require Sodium (for example Better Block Entities or Iris) can't be used with this build.
• Mods that call OpenGL directly can't draw on the Metal backend. To switch mcopt's renderer off, add mcopt.metal=false to config/mcopt.properties (or launch with -Dmcopt.metal=false).
• Distant Horizons runs on the Metal renderer next to mcopt's own terrain. With DH set to its OpenGL renderer, mcopt switches its renderer off for it.
• Far terrain is experimental. On Macs with fewer than 10 GPU cores, it costs most of the fps.

• Far terrain on by default, with tiers for smaller Macs
• Our own shaders (BSL-level) as an option
• Faster world generation (native noise, bit-exact)
• More exact server-tick and chunk optimizations, held for later alphas
• Faster startup
• Wider hardware testing

Apache License 2.0. Keep the NOTICE file with any copy, and credit mcopt.