Clumps

Clumps is a performance mod created by Jaredlll08. Groups XP orbs together into a single entity, reducing lag from large numbers of orbs in mob farms and grinders. As a performance mod it concentrates on frame rate, loading times, and memory use, and it has been downloaded around 55 million times, which puts it among the options players reach for in this space.

Clumps is built for players who get lag from grinders and big mob farms. It groups nearby experience orbs into single entities, slashing the entity count and lag spikes around XP farms. It is approachable enough to drop into a world and use right away, with little setup required.

The mod is available for Forge, Fabric, and NeoForge, so it fits a range of modpacks and launchers. It currently supports Minecraft 1.20.1, 1.20.4, and 1.21.1, spanning the 1.20.1 to 1.21.1 releases. It runs on both the client and the server, so on a multiplayer server every player who connects needs it installed alongside the server itself.

Because it ships for both Fabric and Forge-family loaders, it slots into most popular modpacks regardless of which side they are built on.

As a performance mod, Clumps is meant to improve how the game runs rather than change gameplay, so it is generally safe to combine with other optimisation mods.

If you are comparing options, similar mods include XP grinder optimisations and Lithium. They cover comparable ground, so the right choice usually comes down to your loader, version, and the rest of your pack.