MemGuard

By
SeishiroNagi

Reduces RAM usage in large modpacks and servers by deduplicating NBT strings and monitoring memory usage, without forced GC freezes.

MemGuard

Lightweight memory helper for modded Minecraft.
Deduplicates repeated NBT strings and keeps an eye on your heap — without ever freezing your game.

🆕 Forge v1.0.5 — no more lag spikes

Older Forge builds (1.0.3 and earlier) forced a full garbage collection every 5 minutes and after every texture atlas upload. In big modpacks that meant a short freeze every few minutes. Version 1.0.5 removes every forced GC: tested in a 364-mod pack, the 609 ms freeze every 5 minutes is gone. If you use MemGuard on Forge, please update.

What MemGuard Does

Feature	Description
NBT String Dedup	Short, repeated NBT strings (item ids, keys, enum names) share one instance instead of being stored thousands of times. Lock-free and size-limited, so it never slows other threads down.
Memory Monitor	Writes a short memory status to the log and warns when heap usage gets risky, so you know when a pack needs more RAM or a lower view distance.
No Forced GC	MemGuard never calls `System.gc()`. The JVM's own garbage collector already runs at the right moments.

MemGuard is a helper, not a miracle: it does not promise specific FPS, MSPT or RAM numbers. For memory leaks, pair it with mods like AllTheLeaks or FerriteCore.

Supported Versions

Loader	Minecraft	Java	Latest build
Forge	1.20 – 1.20.6	17+	v1.0.5
NeoForge	1.21.x	21+	v1.0.4
Fabric	1.21.x	21+	v1.0.1 (update with the same fix coming soon)

Check the Files tab for the exact build per version.

Compatibility Notes

Works alongside FerriteCore and AllTheLeaks.
Safe to run with -XX:+DisableExplicitGC (common in server packs).
If logs mention missing Create classes, check that Create and its addons are on the same update line (Update 5 with Update 5 addons, Update 6 with Update 6 addons). That is not caused by MemGuard.