What C2ME works with.
| Platform | Java Edition |
|---|---|
| Loaders | Fabric |
| Minecraft versions | 1.17.1, 1.18.2, 1.19.4, 1.20.1, 1.20.6, 1.21.1, 1.21.4, 1.21.8, 1.21.11, 26.1, 26.2 |
| Environment | Client, Server |
C2ME, short for Concurrent Chunk Management Engine, is a Fabric mod that spreads Minecraft's chunk generation, loading, and saving work across multiple CPU cores instead of the single main thread vanilla relies on. It covers Minecraft Java from 1.17.1 through the current 26.2 release, is required on the server and optional on the client, and it aims for faster, smoother chunk throughput without changing vanilla world generation itself.
What C2ME changes in Minecraft
Vanilla Minecraft loads, generates, and saves chunks almost entirely on one thread, so a busy server or a player flying with elytra can stall waiting for new terrain. C2ME rewrites that pipeline to run in parallel across available CPU cores. The project's own benchmarks on a 48 core system show up to roughly 34 times vanilla's chunk generation throughput and about 8 times Paper's, with the gains scaling further as thread count rises.
World generation speeds up for anyone pre-generating terrain or exploring fast, elytra flight feels smoother because new chunks arrive before you outrun them, and dedicated servers handle more concurrent players without chunk-loading hitches. C2ME does not alter vanilla world generation or gameplay by default. It only changes how fast the work happens, though the project notes that Minecraft's own world generation is not fully deterministic, so worlds can still vary slightly run to run on the same seed regardless of C2ME.
Installation
C2ME only ships for Fabric, so install Fabric Loader first if you have not already. Drop the C2ME jar into the mods folder for whichever side needs it. A dedicated server always needs C2ME, and it is optional on the client for singleplayer or to keep client and server mod lists matched. The current build lists no required dependencies, though Fabric API is still worth having for the wider Fabric mod ecosystem.
Supported Minecraft versions
- 26.2: current stable release line, fully supported, latest build 0.4.2-alpha.0.43 from August 14, 2026
- 26.3-pre-1: an alpha devbuild is already published for the upcoming pre-release, dated September 1, 2026
- 1.17.1 through 1.21.11: long-term support, receiving critical bug fixes only
Recommended companion mods
C2ME's own documentation recommends pairing it with Lithium and ScalableLux for the biggest performance gains, since Lithium optimizes general game logic while C2ME focuses specifically on chunk generation, loading, and saving. Sodium is not mentioned anywhere in C2ME's description or README. Sodium only changes client-side rendering, while C2ME works on chunk generation and IO, so the two are commonly run together without any documented conflict between them.
See C2ME in action
C2ME demonstration showing faster chunk loading
Questions about C2ME.
4 questions
Is C2ME stable?
Every current C2ME build for the 26.x Minecraft line is tagged alpha or beta on Modrinth, including the newest build for 26.2. The last build the project marked as a full release was 0.3.6.0.0 for Minecraft 1.21.11 in December 2025. C2ME's own documentation tells players to back up worlds before installing, so treat any current build as software still being tested.
Does C2ME work with Sodium and Lithium?
C2ME's documentation explicitly recommends pairing it with Lithium and ScalableLux for the biggest performance gains, since Lithium optimizes general game logic while C2ME focuses on chunk generation and loading. Sodium is not mentioned in C2ME's description or README. Sodium only changes client-side rendering, so the two mods touch different systems and are commonly used together without a documented conflict.
How do I install C2ME?
Install Fabric Loader first, then drop the C2ME jar into the mods folder. C2ME is required on a dedicated server and optional on the client, so a server you host needs it running there, and matching client and server mod lists helps avoid version mismatches when players join.
Which Minecraft version does C2ME support?
C2ME covers Minecraft Java from 1.17.1 through the current 26.2 release, with an alpha devbuild already published for the 26.3 pre-release. Only the newest release and newest pre-release get full support. Older versions stay on long-term support with critical bug fixes only.
