If you install one thing, install Sodium. It rewrites Minecraft's renderer and is the single biggest frame-rate win for most setups. Pair it with a memory mod or two and a culling mod, and you have covered the real causes of lag. All of these are free Fabric mods. One note for Opal users: Lithium is a common pick that is not compatible with Opal, so it is the one to leave out.
- Sodium is the single biggest FPS win. Install it first.
- FerriteCore and ModernFix cut memory; Entity Culling skips hidden mobs.
- Lithium smooths game logic but is not compatible with Opal. Skip it if you run Opal.
- Sodium gives the headroom that makes room for a client like Opal.
The stack
Free performance mods
FreeSodium is the core. FerriteCore, Entity Culling, and ModernFix finish it. Lithium is great on non-Opal setups only.
- Sodium (rendering FPS, works with Opal)
- FerriteCore (lower memory use)
- Entity Culling (skip hidden entities)
- ModernFix (load time and memory)
- Lithium (game logic, not compatible with Opal)
Sodium
The rendering rewrite. It replaces the vanilla render path with a faster one and usually makes the largest single difference, especially on weaker GPUs. Needs the Fabric loader and Fabric API first. Runs fine alongside Opal.
FerriteCore
Cuts Minecraft's memory use by reworking how data is stored in RAM. Lower memory pressure means fewer garbage-collection pauses, one of the quiet causes of stutter.
Entity Culling
Stops the game from rendering entities you cannot actually see, behind walls or underground. On busy worlds with lots of mobs or item frames, it claws back frames for free.
ModernFix
A broad fixes-and-performance mod that speeds up load times and trims memory. A safe catch-all once the core mods are in.
Running Opal? Skip Lithium
Lithium is the usual game-logic pick, but it is not compatible with Opal. Rely on Sodium for performance and leave Lithium out of the folder.
At a glance
| Mod | What it fixes | Works with Opal |
|---|---|---|
| Sodium | Rendering FPS | Yes |
| FerriteCore | Memory use | Yes |
| Entity Culling | Wasted entity rendering | Yes |
| ModernFix | Load time and memory | Yes |
| Lithium | Game-logic performance | No |
Where Opal fits
Opal is a Fabric mod for Minecraft 1.21.10, so it installs into the same mods folder as the performance stack. You keep your framerate and add a full client on top: 200+ features across combat, movement, visual, and utility, a glass UI, and a scripting engine. Opal is a large mod, so keep Sodium in for headroom and leave Lithium out, and the setup holds together.
FAQ
Sodium. It rewrites rendering and is the biggest single gain for most machines.
No. Use Sodium for performance and leave Lithium out when Opal is installed.
No. These are speed mods. For shaders, add Iris separately.
