What is Lithium?
Lithium by CaffeineMC optimizes the game's simulation: mob AI, pathfinding, collisions, block ticking, chunk serialization, and dozens of other hot paths, rewritten for speed while producing identical gameplay results. The project's rule is "no compromises" — if an optimization would change vanilla behavior, it does not ship.
It runs on Fabric and NeoForge, on clients and servers alike, and server owners routinely report tick-time cuts of 30 to 50 percent.
Where It Helps
- Servers: the headline use case. Worlds heavy with entities — mob farms, villager halls, animal pens — tick dramatically faster.
- Single-player: the integrated server benefits identically, smoothing worlds with big automation.
- What it does not do: rendering (Sodium's job) and memory footprint (FerriteCore's job). The trio together covers the classic performance stack.
- Configuration: none needed. A properties file allows disabling individual optimization groups for debugging edge-case mod conflicts, which are rare.
Because behavior is bit-identical, Lithium is safe on technical-Minecraft servers where redstone and mob mechanics must match vanilla exactly.
Lithium FAQ
Does Lithium change vanilla mechanics?
No. Its design rule excludes any optimization that alters game behavior; farms, redstone, and mob AI behave exactly as vanilla.
Client, server, or both?
Both benefit independently. Install it everywhere; no sync requirement exists between client and server copies.