What Ixeris works with.
| Platform | Java Edition |
|---|---|
| Loaders | Fabric, NeoForge, Quilt, Forge |
| Minecraft versions | 1.16.5, 1.18.2, 1.19.4, 1.20.6, 1.21.11, 26.1.2, 26.2, 26.3 |
| Environment | Client |
The Ixeris mod optimizes event polling, so less CPU time that could go to rendering is spent on input. It ships for Fabric, NeoForge, Quilt and Forge, and it is client-side only. A server does not need it and does not support it.
Loaders and versions
- Fabric and Quilt: Minecraft 1.16.5 to 26.3. The newest build needs no dependencies.
- NeoForge: Minecraft 1.21 to 26.3. The newest build needs no dependencies.
- Forge: Minecraft 1.16.5 to 1.21.11. The newest build needs no dependencies.
What Ixeris changes
Turning the camera costs frames partly because the game has extra work to do, such as chunk visibility. The rest is waste. Native event polling is inefficient and the JNI upcall overhead adds to it, so CPU time that could go to rendering is spent on input instead. The effect is strongest on Windows with a high-polling-rate mouse.
- Threaded event polling. Polling runs on the main thread and rendering is moved to a separate render thread.
- Buffered raw input (Windows only). Input is read with GetRawInputBuffer, one call for all pending events, instead of GetRawInputData once per event. Doing this in Java code also removes the JNI upcall overhead.
- GLFW state caching. Frequently used GLFW states are cached so other mods can read them from the render thread without a round trip to the main thread.
- A rewritten FPS limiter. It sleeps precisely, then spin waits when the remaining time is very short. It matters for versions before 26.1, where the vanilla limiter does not suit the render thread.
Benchmarks from the creator
In a superflat world with no entities and the mouse grabbed, an 8000 Hz mouse went from 12 FPS without Ixeris to 121 FPS with buffered input on Windows. At 2000 Hz the figures were 76 and 135 FPS, and at 500 Hz they were 134 and 151. The gain shrinks as the polling rate drops, so a standard mouse will see a modest change.
Installing Ixeris
Pick the build that matches your loader and Minecraft version, then drop the .jar into the mods folder. If you have not set up a loader yet, follow the guide to installing Fabric or the one for Forge and NeoForge. The newest builds need no other mods.
The trade-off is that it changes how threads are used. In its current state Ixeris should not break thread safety, and the thread-safety requirements in the GLFW documentation have been strictly obeyed since 3.1.0.
Questions about Ixeris.
5 questions
What does the Ixeris mod do?
Ixeris moves input event polling to the main thread and renders on a separate thread. On Windows it also reads raw mouse input in batches instead of one event at a time. Both changes reduce CPU time wasted on polling, which helps most with high-polling-rate mice.
Does Ixeris work on servers?
No. Ixeris is a client-side mod, and servers are unsupported. You install it only on the player's own game, and it does not need to be on a server for you to join one.
Which loaders does Ixeris support?
Ixeris has builds for Fabric, Quilt, NeoForge and Forge. Each build must match your loader and your Minecraft version. The newest builds for all four loaders need no additional dependencies.
Will Ixeris improve FPS with a normal mouse?
Only slightly. The creator's Windows tests show a large jump at 8000 Hz, from 12 to 121 FPS, but only 134 to 151 FPS at 500 Hz. The benefit grows with the mouse polling rate and is largest on Windows.
Is Ixeris only for Windows?
No. Threaded event polling applies on every platform, and the creator measured gains on Linux with X11 and Wayland. Only the buffered raw input feature is Windows-only.
