BadOptimizations

BadOptimizations
A collection of mostly micro optimizations that add up to something bigger!

What does it do?
Multiple things:
- Avoid updating lightmap
Updating lightmap textures are one of the most expensive parts of the client tick. During each tick, the client will do vector math to calculate lightmaps for blocks and the sky, then upload that new texture to the GPU. However, this can be completely avoided and cached if nothing affecting block brightness has changed. This mod will cancel lightmap updates if nothing that changes block brightness (e.g. gamma slider, potion effects, dimension) has changed.
- Don't do debug logic if we don't need to
Minecraft has four debug renderers that can be activated with a debug server: bees, game events, game test and villager AI. Even if there's nothing to process, the logic for these debug renderers are still executed. This mod will only execute them if debug is enabled and there is data from the server to process.
- Sky color calculation optimizations (1.21.10 and below)
Minecraft uses a cubic color sampler every frame to calculate the current sky color. This function loops 216 times to factor in surrounding biomes, even if all surrounding biomes are identical or have identical sky colors. This mod makes the color sampler only used if you are between biomes with different sky colors, and caches it for each tick. Otherwise, a shorter, simpler and faster sky color calculation is used.

That's a few of them, at least.
You can disable any optimization in the config file if you need to.

How much does it help?
Depends on your system and luck, but on my own PC, an RTX 3060, intel i7 12700 and 4GB of allocated ram on Fabulously Optimized:
Without toasts, it goes from 1926-1955 FPS:

To 2008-2023 FPS:

And with toasts, it goes from 1351-1384 FPS:

To 1414-1458 FPS:

My mod is incompatible!
You can mark your mod as incompatible with specific BadOptimizations options. If your mod is present, BadOptimizations will automatically disable the specific options you specify.
You can also add hooks that tell BadOptimizations when the lightmap or sky color needs to be updated instead of adding a hard incompatibility to the caching optimizations.

Dependencies?
None.

(Also available on CurseForge, if that's your thing.)

ABOUT THIS LISTING

This page describes BadOptimizations by thosea. The description and screenshots are the author's own, imported from their listing on Modrinth on 31 August 2026: https://modrinth.com/mod/badoptimizations

Mythiq.net hosts no files for it. The download button goes straight to the release file on cdn.modrinth.com, so you are downloading from the author's own host, not from a copy of ours.

The download count, rating and comments on this page start at zero and count Mythiq.net only. The source's own figures are not copied here — they measure a different site, and a number that cannot be checked against our own ledger is not worth printing.

MOD LOADER

This release is built for Fabric. A mod built for one loader will not load under another — Fabric mods do not run on Forge, and vice versa.

GAME VERSION

Built for Minecraft 26.2. Minecraft mods are tied to an exact version: a 1.21.4 build will refuse to load on 1.21.5.

DEPENDENCIES

Check the author's listing for required libraries before you start the game — a missing dependency shows up as a crash on launch, not as a warning.

1. Install Fabric for the Minecraft version you play, if you have not already.

2. Download the .jar with the button on this page. Do not unzip it — a mod jar is installed as it is.

3. Put it in your mods folder:

Windows — %APPDATA%\.minecraft\mods

macOS — ~/Library/Application Support/minecraft/mods

Linux — ~/.minecraft/mods

4. Launch the game with the Fabric profile selected.

ON A SERVER

Anything that changes world generation or gameplay has to be installed on the server as well as on every client. Client-side visual and interface mods do not.

UPDATING

Replace the old .jar rather than adding the new one beside it. Two versions of the same mod in the folder is a crash on launch.