
Modrinth · Minecraft mod
KAllFix
Optimization and multithreading written by n1luik
Quick answer
Which KAllFix release should I use?
KAllFix 1.0.3.14 targets 1.20.1 with Forge. Installation on the client is optional. Installation on the dedicated server is optional. No extra mods listed for this file.
Where it goes
Is KAllFix required on the client, server, or both?
Installation on the client is optional. Installation on the dedicated server is optional.
The source marks this as usable on both the client and server.
What else does KAllFix 1.0.3.14 need?
1.0.3.14. Change the file and its required mods may change too.
This file does not list any required mods. Do not add a library just because a different file uses it.
This file does not list any required or optional mods.
Before you install it
Add KAllFix without breaking your instance.
Built for KAllFix 1.0.3.14. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use 1.0.3.14. It targets 1.20.1 with Forge; another release may have different loader, side or dependency requirements.
- 02
Bring the mods it needs
This file does not list any required mods. Do not add a library just because a different file uses it.
- 03
Put it on the correct side
Installation on the client is optional. Installation on the dedicated server is optional.
- 04
Pick the file you checked
Use the “Get this file” button beside 1.0.3.14. It opens that exact file at the source.
About this project
What does KAllFix add?
Overview
- This project is used to fix and optimize issues caused by other mods, and it works on servers.
- The project contains two main parts:
k_all_fixandk_multi_threading, with features mainly controlled by JVM parameters. - No regular config file is provided; configuration is mainly done through startup parameters.
- Client-side usage is supported from
1.0.4.0onward (requires JVM parameter-DKMT_Client=true). - Under a multi-mod and single-threaded baseline environment, cause no issues is not guaranteed, but you could create an ISSUE on Github and the author will fix it quickly.
- With some mod combinations, clients may still need to install this mod even if it has no visible effect.
Features and Use Cases
Optimizations
- Optimizes performance for Upgraded Additional Trims.
- Optimizes the April Fools date-check related overhead in Atmospheric.
- Optimizes performance for Upgraded Core.
- Optimizes chicken-coop AI performance in [Let's Do] Farm & Charm.
- Optimize performance for Event Wrapper
- Optimize performance for Create:FluidLogistic
-DKAF-fluidlogistics.DisabledDynamicUp=trueto disable updating old id, if not do so, may cause to preformance slow down.
- Optimize AE2 game computation
- Optimize performance for ItemStack.issameItemsameTags
- Optimize performance of PPMO2
- Delete useless code of Apotheosis and Create:Connected
Fixes
- Fixes performance issues related to entity counts in L_Ender's Cataclysm when used on servers with MineColonies.
- Fixes excessive invalid packet sending in [Let's Do] Farm & Charm.
- Fixes compatibility issues between Biolith and some MCreator worldgen mods (e.g., Terramity).
- Fixes compatibility issues between Gregicality Rocketry and Canary, but collision-box issues may still occur at space-station borders.
- Fixes the issue where Petrolpark's Library 1.4.2 is unusable in some Java environments; this fix can be disabled with
-DKAF-DisablePetrolpark=false. - Fixes/optimizes magnetic-field-related performance issues in Alex's Caves.
- Fixes mixin performance issues in Create: Diesel Generators.
- Fixes server crashes in older Destroy versions caused by database connection failures.
Multithreading
Introduction
- Multithreading supports includes block ticks, block entity ticks, entities, dimensions, player packet receiving (manual toggle, client-only), and player login (manual toggle), and also fixes some problematic single-threaded mods by applying multithreading.
- Multithreading is enabled by default on the server side.
- In multithreaded scenarios, thread-pool interception or limit-exceeded errors may appear, but they usually do not crash the server.
- It is recommended to manually set
-DKMT-threadMax=[CPU thread count]; otherwise world generation may be frozen. If freezes still occurs after setting it, increase the value higher. - Before
1.0.4.0, clients cannot use multithreading; from1.0.4.0onward, clients can enable it via-DKMT_Client=true. - After
1.0.3.3,ParaServerChunkProvider,TaskRun, and some chunk generation code depend more heavily on C2 compilation (the JVM will enter C2 automatically after running for a while). - In Windows Server 2022 Datacenter 21H2 20348.3091 (author's environment), rare thread scheduling anomalies may occur and causes abnormally high CPU usage; the solution is to restart the server.
Related JVM Parameters
-DKMT-threadMax=[number]- Sets thread-pool thread count.
-DKMT-callMax=[number]- Sets the default maximum number of threads that multithreaded tasks may use.
-DKMT-ThreadpoolKeepAliveTime=[milliseconds]- Sets how long idle threads are kept before recycling.
-DKMT_D=[any characters]- Disables multithreading.
-DKMT-OpenVanillaServerChunkCache=true- Forces the vanilla
ServerChunkCachefix path (added in 1.0.5.3).
- Forces the vanilla
JVM Parameter Overview (all retained)
Basic and General
-DKAllFix_D=[any characters]- Disables KAllFix.
-DKMT_Client=true- Enables multithreading-related features on the client side (1.0.4.0+).
-DKAF-DisablePetrolpark=false- Disables the Petrolpark's Library 1.4.2 related fix.
Connection and Timeout
-DKAF-ClientboundKeepAlivePacket_Max=[milliseconds]- Changes the timing requirement for
ClientboundKeepAlivePacket(default 15 seconds; vanilla must be <30 seconds or the player is kicked for timeout).
- Changes the timing requirement for
-DKAF-ServerTimeout=[seconds]- Sets server connection timeout.
- May be ineffective in some cases (both parameters are needed because Forge's
forge.readTimeoutonly covers server packet-read timeout, not client/server network threads with players).
-Dforge.readTimeout=[seconds]- Forge packet-read timeout parameter (used together with the previous parameter).
Mixin / NBT / Auto Command
-DKAF-RemoveMixin:[class name]- Disables a specified mixin (
k_multi_threadingmixins can also be disabled).
- Disables a specified mixin (
-DKAF-NbtIoMixin_NotGZip=true- Adds try-catch to NBT IO for non-gzip scenarios (unsafe; requires commons-compress in the environment).
-DKMT-ChunkGeneratorMode2Start=[true,false]- Automatically runs:
/SetterWorldConfig world setM2 %%KMT-ChunkGeneratorMode2Start%%.
- Automatically runs:
Breeding Control
-DKAF-ChunkBreedingControlSize=[number]- Disables breeding when chunk entity count exceeds the given value; disabled if the parameter is missing / not a numeric array / empty.
-DKAF-ChunkBreedingControlSizeEnable=[true,false]- Internal cache switch for detection results; manual setting may be overridden by the program.
Optional Features
-DKMT-SafeUnloadChunk=true- Enables chunk unload in chunk-generation threads (recommended only for
<1.0.4.2when related freezes occur).
- Enables chunk unload in chunk-generation threads (recommended only for
-DIndependencePlayer=true- Enables asynchronous player handling (likely provides little to no optimization).
-DFixBiolithBugMode2=true- Attempts to fix most Biolith compatibility issues (may introduce major bugs).
-DKAF-gtceu.MedicalConditionTrackerMixin=true- Disables radiation in GTM.
-DKAF-RemoveClientboundKeepAlivePacket=true- Disables vanilla
ClientboundKeepAlivePacket(pingcan no longer be calculated).
- Disables vanilla
-DKAF-RemoveFlyingTest=true- Removes flight checks.
-DKAF-moonrise_fast_palette=true- Disable the
fast_palettefeature from Moonrise.
- Disable the
-DKAF-FixTFMGDestroy=true-DKAF-Fix_fabric-object-builder-api.jar=true- Fixes compatibility between Sinytra Connector's
fabric-object-builder-apiandforge-47.3.27.
- Fixes compatibility between Sinytra Connector's
-DKAF-FixAllPacket=true- Fixes network packets (must be enabled on both client and server); related mods: Mekanism Explosives, Create, The Abyss II.
-DKAF-ChunkAwareBlockCollisionSweeperFast=true- Use approximation algorithm to replace ChunkAwareBlockCollisionSweeper of Lithium
Login Multithreading
-DKMT-LoginMultiThreading=true- Enables multithreaded login.
-DKMT-LoginMultiThreading.ConnectionLock=true- Waits for async execution completion at tick end (disabling may improve performance somewhat, but lowers login stability and may crash).
-DKMT-LoginMultiThreading.TaskSizeMax=[number]- Limits the number of concurrent login tasks (default 8).
- Login multithreading may cause the server to receive
ServerboundMovePlayerPacketearly, leading to one error log.
Packet Optimization
-DKAF-packetOptimize=true- Optimizes some vanilla packets (must be enabled on both client and server).
-DKAF-packetOptimize.AttributesReOutputTime=[milliseconds]- Sets forced resend interval for attribute-related data (default 2 minutes).
-DKAF-packetOptimize.CompatibilityMode.ClientboundBlockEntityDataPacket=true- Uses more conservative compression for
ClientboundBlockEntityDataPacket(impacts performance).
- Uses more conservative compression for
-DKAF-packetOptimize.CompatibilityMode.ClientboundSectionBlocksUpdatePacket=true- Uses more conservative compression for
ClientboundSectionBlocksUpdatePacket.
- Uses more conservative compression for
Others
-DKAF-UnsafeCinderscapesFix1=true- Adjusts limits for the high-overhead
enableAshFallfunction in Cinderscapes.
- Adjusts limits for the high-overhead
-DKAF-fix.asynchronous.ClientboundCustomQueryPacket=true- Makes handshake asynchronous, reducing the chance of being unable to join when too many mods are installed.
-DKAF-FixConfigAuto=true- Automatically changes some config options for compatibility.
Installation and Runtime Notes
- From
1.0.3.18, it can run directly (installation feature is still kept). - Before
1.0.3.18, run the mod's installer first, or use:java -jar k_multi_threading-xxx.jar -i [empty or install directory]
- Installation only generates
k_multi_threading-base.jarandk_multi_threading-asm.jar. - Some features may download dependencies (
Zstd-jni 1.5.7-2); if download fails, place them manually ingame_directory/lib.
Compatibility Notes
- Using
-DKAF-FixConfigAuto=truecan automatically disable: - Cases where
-DKAF-FixConfigAuto=trueshould not be used:- Possible conflict with
mixin.perf.cache_upgraded_structuresin ModernFix (disable viamixin.perf.cache_upgraded_structures=falseinconfig/modernfix-mixins.properties). - With login multithreading enabled, ParCool (listed as Parkour on page) may require one death after player joining before working normally.
- Ars Creo may rarely log
Modifier is already applied on this attribute!, but will not crash. - NuclearCraft: Neoteric fission reactors may rarely calculate cooling incorrectly after server restart.
- Possible conflict with
Commands
/debug_GetterClassFile [class name]- Exports final runtime class data to the game directory, with filename format
timestamp_save.class.
- Exports final runtime class data to the game directory, with filename format
/SetterWorldConfig [world, ClearErrorSize, RemoveRemoveErrorSize]- Settings from this command are not persistent.
ClearErrorSize: clears the recorded count of “errors that caused server crash risk”.RemoveRemoveErrorSize: stops recording crash-risk counts and keeps intercepting.- Under
world [dimension registry id], available options:setM2 [true,false]: switches to another dimension implementation mode; higher priority thansetMultiThreading, but may freeze the game.setMultiThreading [number](default0): sets multithread parallel task count for this dimension; independent mode fromsetM2, and may also freeze the game.
Others
- Because Minecraft and many mods are fundamentally designed around single-threaded behavior, complete fixes for all issues cannot be guaranteed.
Source Code Usage
moonrise_fast_paletteuses source code from Moonrise.- Compatibility fixes for Gregicality Rocketry and Canary use source code from Canary.
Project description from Modrinth.
Pick your setup
KAllFix by Minecraft version and loader
Choose the version and loader you play, then open the matching release.
1.21
1 loader build1.20.1
1 loader build1.19.2
1 loader buildCheck the dependencies, then try the file in a copied instance before changing a world you care about.
Recent files
KAllFix versions and loaders
1.1.0.4
k_multi_threading-NeoForge-1.1.0.4.jar
10 Aug 2026
1.1.0.4
k_multi_threading-1.1.0.4.jar
10 Aug 2026
1.1.0.3
k_multi_threading-NeoForge-1.1.0.3.jar
3 Aug 2026
1.1.0.3
k_multi_threading-1.1.0.3.jar
3 Aug 2026
1.1.0.2
k_multi_threading-NeoForge-1.1.0.2.jar
18 Jul 2026
1.1.0.2
k_multi_threading-1.1.0.2.jar
18 Jul 2026
1.1.0.1
k_multi_threading-1.1.0.1.jar
15 Jul 2026
1.1.0.1
k_multi_threading-NeoForge-1.1.0.1.jar
15 Jul 2026
1.1.0.0
k_multi_threading-1.1.0.0.jar
8 Jul 2026
1.1.0.0
k_multi_threading-NeoForge-1.1.0.0.jar
8 Jul 2026
1.0.5.14
k_multi_threading-1.0.5.14.jar
30 May 2026
1.0.5.13
k_multi_threading-1.0.5.13.jar
29 May 2026
Looking for an older file? The official Modrinth project page is in Resources.