| name | minecraft-client-expert |
| description | Expert knowledge for Minecraft Java Edition client optimization on Windows โ FPS settings, NeoForge performance mods, shader configuration (Iris/Oculus), JVM flags, and PrismLauncher instance management. Auto-loads when discussing Minecraft performance, mods, shaders, or configuration. |
| triggers | ["minecraft","neoforge","minecraft fps","minecraft mods","optifine","iris shaders","oculus mod","embeddium","prism launcher","prismlauncher","shader pack","jvm flags minecraft","minecraft optimization","java edition minecraft"] |
| invocable | true |
Minecraft Client Expert
Comprehensive reference for Minecraft Java Edition client optimization on Windows.
Scope: client-side FPS, NeoForge modded performance, shaders (Iris/Oculus), JVM tuning, PrismLauncher management.
Quick Reference
Scope
- Edition: Java Edition only
- Loader: NeoForge (primary), Forge (secondary)
- Platform: Windows only (PowerShell for system commands)
- Launcher: PrismLauncher
- Focus: Client FPS, shaders, modded performance
Core Principles
- Embeddium > OptiFine for NeoForge. OptiFine is unmaintained for modern modded play.
- Iris/NeOculus > OptiFine shaders โ better FPS, mod compatibility, faster updates.
- ZGC Generational > G1GC for Java 21+ clients. Lower pause times, better frame consistency.
- FerriteCore + ModernFix are non-negotiable in any modpack for RAM reduction.
- Always profile first โ run hardware detection before recommending settings.
Known Configurations
User's BMC5 instance (NeoForge 1.21.1) is a validated reference baseline:
- JVM:
-XX:+UseZGC -XX:+ZGenerational -XX:+AlwaysPreTouch -XX:+UseStringDeduplication -XX:+UnlockExperimentalVMOptions -XX:+AlwaysActAsServerClassMachine -XX:+DisableExplicitGC -XX:+UseNUMA -XX:ReservedCodeCacheSize=400M
- Memory: 8192 MB min/max, PermGen 1024
- Java: Microsoft JDK 21 (bundled by PrismLauncher)
When to Read Reference Files
Read FPS-OPTIMIZATION.md when:
- User reports low FPS without a clear cause
- Asking for vanilla/base game settings to tweak
- Windows-level GPU and process optimizations needed
Read SHADERS.md when:
- Installing shaders for the first time
- Shader FPS is too low โ need to tune settings
- Choosing between shader packs for a given GPU tier
Read NEOFORGE-MODS.md when:
- Building or auditing a performance mod stack
- Diagnosing mod compatibility (Moonrise vs C2ME, Embeddium vs Rubidium)
- Looking for the right mod for a specific bottleneck (RAM, entity lag, startup)
Read JVM-FLAGS.md when:
- Configuring memory allocation (Xmx/Xms)
- Choosing garbage collector (ZGC vs G1GC)
- Selecting Java version for a Minecraft version
- Crashes with OutOfMemoryError or severe GC pauses
Read PRISM-LAUNCHER.md when:
- Creating or importing an instance
- Configuring per-instance Java/memory overrides
- Understanding instance.cfg and mmc-pack.json schemas
Read SYSTEM-PROFILING.md when:
- Starting a new optimization session without hardware info
- Need PowerShell commands to detect GPU, VRAM, CPU cores, RAM
- Checking installed Java versions on Windows
Read cookbook/optimize-instance.md when:
- Setting up a new NeoForge instance from scratch
- Doing a full optimization pass on an existing instance
- User wants a guided, step-by-step workflow