Smootheim

Smootheim 0.2.2

Server-side networking, save and player-join optimizations for Valheim dedicated Steam servers. Clients need no mods.

Smootheim spreads outgoing replication work fairly across players, increases the Steam send allowance and rate, reduces join sorting work, and serializes saves incrementally. It also skips unused dedicated-server terrain rendering work and defers asset collection within time and memory limits.

In our testing this mod is sufficient to:

• Enable enjoyable transcontinental play (>60ms RTT, players can reliably parry!)
• Eradicate most lag from saves
• Eradicate most lag from player joins

Requirements

• Dedicated Steam server: Valheim 1.0.16 / build 25527701, 1.0.15 / build 25390671 or

1.0.12 / build 25253791, network version 40.

• BepInExPack_Valheim 5.4.2350.

This supplies the tested BepInEx 5.4.23.5 and HarmonyX 2.9.0 combination.

• Native integration has been tested on Linux x86-64. Windows is unverified.

No client-side installation is needed. In this release, optimizations activate only on dedicated servers using Steam transport (crossplay off).

Install

Back up the world before installing or updating.

With a Thunderstore-compatible manager, install Smootheim into the profile used to launch your dedicated server. The manifest declares the BepInEx dependency.

For manual installation, install the required BepInEx pack first, then copy this archive's BepInEx/plugins/Smootheim/ directory into the server's matching directory. Keep all three DLLs together and remove any duplicate older Smootheim installation. This public package contains only the mod; it supplies no loader or configuration files. The separate Linux AMP bundle includes both.

Start with Steam transport (crossplay off). Confirm these entries in BepInEx/LogOutput.log:

Loading [Smootheim 0.2.2]
preflight=passed
patches=installed
Smootheim active; activation=enabled transport=Steam

Loading the plugin alone does not establish activation.

Configuration

First launch creates BepInEx/config/pub.rag.smootheim.cfg. Stop the server before editing; changes require restart. Existing settings are preserved.

| Section / setting | Default | Purpose | | --- | --- | --- | | Networking / Enabled | true | Enable optimizations after compatibility checks | | Networking / SchedulerEnabled | true | Fair, budgeted peer scheduling | | Networking / SchedulerBudgetMs | 1 | Soft work allowance per frame | | Networking / SendWindowBytes | 32768 | Outstanding send allowance | | Networking / SteamSendRateBytesPerSecond | 524288 | Per-connection Steam send rate | | Networking / DirtySyncMode | Enabled | Candidate tracking; Off, Shadow or Enabled | | Performance / JoinSortEnabled | true | Reduce join sorting work | | Performance / SelectedSaveSnapshots | true | Snapshot selected save data | | Performance / BudgetedSaves | true | Incremental capture; requires SelectedSaveSnapshots | | Performance / SkipTerrainRenderMesh | true | Skip unused terrain visual mesh work | | Performance / DeferAssetCollection | true | Defer collection within configured limits |

Disable or remove

Set Networking / Enabled = false and DirtySyncMode = Off, then restart for a vanilla networking baseline. To remove the mod, stop the server and remove all three DLLs from BepInEx/plugins/Smootheim/.

When reporting a problem, include the game build, mod version, server platform, configuration, other mods and share complete logs.

Developer diagnostics

These features are for development and maintainer-directed troubleshooting, not intended for end users. Leave them at their defaults unless the maintainer requests a diagnostic run. They are grouped under [Troubleshooting] at the end of the config file, separately from networking and performance settings.

| Setting | Default | Purpose | | --- | --- | --- | | MetricsIntervalSeconds | 300 | Aggregate network metrics; 0 disables | | DirtySyncIntervalSeconds | 300 | Dirty tracking summaries; 0 disables | | ReceiveEnabled | false | Temporary incoming ZDO profiler | | ReceiveIntervalSeconds | 300 | Profiler summary interval; requires ReceiveEnabled | | HealthEnabled | false | Greydwarf health/owner comparisons; requires ReceiveEnabled | | ChatSpawnEnabled | false | Admin creature-spawning test command; changes the world and may be saved |

License

Required Notice: Copyright 2026 James Tucker

Smootheim is licensed under PolyForm Noncommercial 1.0.0. The complete terms and copyright notice are included in LICENSE and LICENSING.md under BepInEx/plugins/Smootheim/ in the archive.

I will gladly provide copyright-assigned patches and technical guidance to Iron Gate if they are willing to upstream these improvements into Valheim. Alternative licensing for hosting providers is available only on request and by separate agreement. These statements do not grant an exception to the license.