Alex Caves Mod performance: RAM, shaders and settings

Alex's Caves puts a lot of work into how each biome looks and sounds: custom fog, particles, light colours and music. That makes the atmosphere memorable, and it means the mod benefits from a few sensible settings.

How much memory to allocate

There is no official minimum from the developers, and the right number depends on your other mods. As a starting point, many players give a Forge 1.20.1 instance with a mid-sized modpack around 6 GB, and larger packs 8 GB. With Alex's Caves on its own, 4 GB is often enough.

More is not always better. Allocating nearly all of your computer's memory can cause stutters, because the system and Java's garbage collector have less room to work. Leave several gigabytes for your operating system.

In the official launcher, open Installations, edit the Forge profile, choose More options and change the -Xmx value in the JVM arguments (for example -Xmx6G). Most third-party launchers have a memory slider in the instance settings.

Why shaders are discouraged

The mod's own description recommends playing without shaders. Each biome has its own fog, brightness and light colour, and many shader packs replace those effects with their own. The result can look washed out or simply wrong, and some combinations cost extra performance on top.

If you really want shaders, try them in a test world, visit each biome, and turn them off whenever something looks broken.

In-game settings that help

• Render distance: the single biggest lever. Underground, you rarely need a long view distance.
• Simulation distance: lowering it reduces how many creatures and blocks are updated around you.
• Particles: setting particles to Decreased helps in busy biomes, at some cost to atmosphere.
• Entity distance: reducing it trims how far away creatures are drawn.

Expect a slower first load

The first world creation and the first visit to a new biome take longer, as new terrain and assets are prepared. That's normal and doesn't mean something is wrong.

On servers

For a multiplayer server, memory needs grow with player count and the number of loaded areas. If the server lags, use a profiling tool to see what's actually taking time before changing settings at random. The config files that the mod generates in the config folder let server owners adjust many options; back them up before editing.

Still struggling?

If performance problems come with crashes or errors, the troubleshooting guide is the next stop. For a clean setup from scratch, see the installation guide.