OptiLoad

OptiLoad — Forge 1.20.1 (Maybe future and past versions) load-time and RAM helper for huge packs.

Cuts the slow parts of startup: zip datapacks, recipes, advancements, and tags are cached to disk and reused on later launches. Optional model-bake cache (off by default). Distant mob AI is frozen unless a player is nearby (FTB Chunks force-loaded chunks stay active).

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Proof of concept — [Mystic’s Monstrosity – Greedy Edition](https://www.curseforge.com/minecraft/modpacks/mystics-monstrosity-greedy-edition)  

~1700 mods, Forge 1.20.1. Same machine, same pack. Timed 31 Aug 2026 (JVM start → title screen; world ProgressScreen → player interactive).

| Stage | Without OptiLoad | With OptiLoad | Saved |

|—|—|—|—|

| Boot to title screen | 21m 53s | 7m 53s | 14m (~2.8× / 64% faster) |

| World to playable | 2m 20s | 2m 03s | 17s (~12% faster) |

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What it does

– Extracts zip datapacks into the world `optiload_cache` folder so they are not held as zips in RAM

– Disk cache for recipes, advancements, and heavy tags (items/blocks/entities/fluids/biomes)

– Soft in-memory copies for faster reloads; dropped after load so Minecraft keeps the only live data

– Optional baked-model cache (off by default; auto-disabled if ModernFix `dynamic_resources` is on)

– Mob AI only within `aiActivationRadius` (default 10 blocks); named mobs stay active; FTB force-loaded chunks respected

Config: `optiload-common.toml`  

Works on client and server. Safe to add to an existing world.