Unstable SMP Simulator

What is Unstable SMP Simulator?

Unstable SMP Simulator is a Fabric modpack for Minecraft 1.21.11, published by Hi_Its_I on Modrinth since 2026.

The latest release, 1.21.11-7.1 from Nov 10, 2026, declares 24 mods. Across 36 published versions it has covered Minecraft 1.21 through 1.21.11.

With 143K downloads it ranks #146 of the 518 most-downloaded Modrinth modpacks we track, and its authors tag it as adventure, challenging and combat.

• Adventure
• Challenging
• Combat

Most widely used mods in Unstable SMP Simulator

The latest version declares 24 projects. The ones below appear in the most packs we track.

• FerriteCore
• Entity Culling
• Sodium
• Fabric API
• ImmediatelyFast
• Lithium
• Mod Menu
• Iris Shaders
• Sodium Extra
• AppleSkin
• Text Placeholder API
• Clumps
• MaLiLib
• Litematica
• ukulib
• Carpet
• uku's Armor HUD
• Immersive Optimization
• BetterHurtCam
• Modify Player Data
• Carpet crit fix
• Carpet mace fix
• VexBot
• Wither Death Sounds

Full Unstable SMP Simulator mod list

8 more files are bundled inside the pack without a Modrinth project, so we cannot name them.

How its mod list compares

Less common picks: 5 mods found in five or fewer tracked packs.

• Carpet crit fix
• Carpet mace fix
• VexBot
• Wither Death Sounds
• Modify Player Data

Packs with the most mods in common

• UnstableSMP - 2v1000 Fight Fabric for 1.21.11 17 mods in common
• One Block ModPack Fabric for 1.21.10 9 mods in common
• Better PvP Fabric / Forge for 26.2 13 mods in common
• Essentially Optimized (FPS) Fabric for 26.3 10 mods in common
• Spunky Boost Fabric for 26.3 12 mods in common

What kinds of mods are in Unstable SMP Simulator?

Of its 24 mods, 15 are tagged utility, 8 optimization and 6 library. Mods can carry several tags, so the counts overlap.

At 21% game mechanics, that is a larger share than 95% of the 491 packs we track.

• utility: 15 (63%)
• optimization: 8 (33%)
• library: 6 (25%)
• game mechanics: 5 (21%)
• cursed: 2 (8%)
• equipment: 2 (8%)

How big is Unstable SMP Simulator?

With 24 mods, Unstable SMP Simulator has fewer mods than 79% of the 491 packs we track and fewer mods than 74% of the 35 on Minecraft 1.21.11.

The pack file is 32.1 MB. 11 mods are client-only and 13 also run on a server. It declares no resource packs or shaders.

How actively is Unstable SMP Simulator updated?

Unstable SMP Simulator was first published on Apr 11, 2026, and has 36 published versions in total.

The latest release, 1.21.11-7.1, is dated Nov 10, 2026, 1 day before our data was fetched on Nov 11, 2026. Releases have covered 2 Minecraft versions over 213 days.

Staple mods Unstable SMP Simulator includes and leaves out

Across the 325 Fabric packs we track, 15 mods turn up most often. Unstable SMP Simulator includes 10 of them; it leaves out Cloth Config API, Fabric Language Kotlin, YetAnotherConfigLib (YACL), Reese's Sodium Options and Architectury API.

How much RAM does Unstable SMP Simulator need?

Unstable SMP Simulator needs 4 GB allocated (3 GB minimum). Our estimate from the 24-mod list, not measured.

How to set allocated memory

How to install Unstable SMP Simulator

Search for "Unstable SMP Simulator" in the Modrinth source of your launcher. Pick version 1.21.11-7.1 for Minecraft 1.21.11 (Fabric). Modpack install guide.

How do I make an Unstable SMP Simulator server?

Unstable SMP Simulator is marked as needing a server-side install, so the server must run the same mods and version as the players.

• Match the version: the latest pack version is 1.21.11-7.1 for Minecraft 1.21.11.
• Loader: Fabric.
• Memory: at least 3 GB (our estimate).

Modpack server guide.

Versions

Newest build for each of 2 Minecraft version and loader pairs.

Official links

• Unstable SMP Simulator on Modrinth (downloads and changelog)
• Issue tracker

Facts on this page come from Modrinth's public API, last fetched Nov 11, 2026. Descriptive text is our own. Spotted an error, or are you the author and want something changed? See disclaimer and takedowns.