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CurseForge · Minecraft mod

Harium

A general-purpose optimization mod that rewrites inefficient vanilla code for AI, redstone, entities, hoppers, and physics without changing game behavior

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Quick answer

Which Harium release should I use?

Updated yesterday
Latest stable file Harium-mc1.20.1-2.0-cumulative-hotfix-v2.jar
Game version 1.20.1
Loader Forge

Harium-mc1.20.1-2.0-cumulative-hotfix-v2.jar targets 1.20.1 with Forge. The project page does not say whether this file belongs on the client, dedicated server, or both. No extra mods listed for this file.

Where it goes

Is Harium required on the client, server, or both?

The project page does not say whether this file belongs on the client, dedicated server, or both.

Client Source doesn’t say
Dedicated server Source doesn’t say
Loader for this release Forge
Required install it here Optional supported, not mandatory Not supported do not install here Source doesn’t say do not assume

The source does not explicitly classify this release as client-only or server-only.

What else does Harium-mc1.20.1-2.0-cumulative-hotfix-v2.jar need?

Harium-mc1.20.1-2.0-cumulative-hotfix-v2.jar. Change the file and its required mods may change too.

No extra mods listed for this file

This file does not list any required mods. Do not add a library just because a different file uses it.

This file does not list any required or optional mods.

Before you install it

Add Harium without breaking your instance.

Built for Harium-mc1.20.1-2.0-cumulative-hotfix-v2.jar. Pick another file and the loader, install side or required mods may change.

  1. 01

    Stick to this file

    Use Harium-mc1.20.1-2.0-cumulative-hotfix-v2.jar. It targets 1.20.1 with Forge; another release may have different loader, side or dependency requirements.

  2. 02

    Bring the mods it needs

    This file does not list any required mods. Do not add a library just because a different file uses it.

  3. 03

    Put it on the correct side

    The project page does not say whether this file belongs on the client, dedicated server, or both.

  4. 04

    Pick the file you checked

    Use the “Get this file” button beside Harium-mc1.20.1-2.0-cumulative-hotfix-v2.jar. It opens that exact file at the source.

About this project

What does Harium add?

Harium | General Purpose Optimization

Smart Performance Through Intelligent Code Replacement


What Is Harium

Harium is a general-purpose optimization mod (based on Lithium) that rewrites inefficient vanilla code with faster, smarter implementations — without changing game behavior.

Same Game. Better Performance.

Harium targets the most CPU-intensive systems in Minecraft: entity processing, redstone, AI, hoppers, and physics — replacing slow algorithms with optimized alternatives that produce identical results.


Optimization Categories

Each category can be individually enabled or disabled.

  • AI & Pathfinding: Faster block type lookups, optimized POI searches, removed useless behaviors
  • Entity System: Section-based movement tracking, optimized collision detection, smarter item merging
  • Block & Redstone: Optimized redstone wire power calculations, BlockEntity sleeping for inactive tiles
  • Hopper & Inventory: Event-driven hopper logic with caching — hoppers only scan when inventories actually change
  • Memory Allocations: Eliminates unnecessary object creation in hot code paths using FastUtil collections
  • VoxelShapes: Specialized shape implementations for faster collision detection and ray tracing
  • Collections: Replaces standard Java collections with optimized FastUtil alternatives throughout

Key Technical Approaches

  • Event-Driven Architecture: Block sections notify listeners only when changes occur, instead of polling every tick
  • Caching Layers: Multiple levels of caching for block states, entity positions, and inventory contents
  • Smart Iteration: Chunk-ordered entity iteration for better CPU cache locality and early termination
  • Reduced Locking: Array-based data tracker entries instead of synchronized maps

Fork Information

Harium is a fork of Lithium by jellysquid3.

Compatible: Designed to be fully compatible with vanilla behavior. No gameplay changes.

Credits & Support

Original Lithium created by jellysquid3 and maintained by the community.

Harium extends the optimization coverage with additional improvements.


Join the Community

Get help and updates on our Discord.

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Harium - Maintained by Hari - High Performance Minecraft

Project description from CurseForge.

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Harium by Minecraft version and loader

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1 available setups

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Recent files

Harium versions and loaders

17 of 17 releases match

Looking for an older file? The official CurseForge project page is in Resources.