Valheim: Eliminating Desync & Better Networking
In Valheim, the networking system uses a "Peer-to-Peer within a Dedicated Server" hybrid model. This often leads to the infamous Desync, where one player sees a door as closed while another sees it as open. This is primarily caused by strict internal limits on the "Data Rate" (packet size) the game is allowed to send per second.
Mixed PC + PS5 group? Cross-platform sessions add their own desync flavor. See our Valheim PS5 crossplay guide for the platform-specific networking gotchas.
1. The Packet Cap
Valheim 1.0.17 only queues more world data for a player while less than 10 KB is still waiting, and on the Steam backend each connection sends at a fixed 150 KB/s. In a large base, with thousands of building pieces to keep in sync, that queue fills and everything seems to "freeze" for the player.
2. Crossplay Conflicts
Using the PlayFab (Steam/Xbox Crossplay) backend can sometimes introduce higher latency than the pure Steam socket. Switch to Steam-only if all players are on PC.
3. Building Density
Each building piece is a "ZDO" (Z-Data Object). The more ZDOs in a 64m radius, the more data the server has to push to your client every time you move.
The "Better Networking" Solution
The Better Networking mod raises those limits; install it on both the server and all clients. Check the version first: the original by CW_Jesse was last updated in November 2023 and its newest release, 2.3.2, targets the pre-1.0 game. For 1.0 the working builds are forks by other authors, such as Better Networking PC, which says it runs on 1.0.7 to 1.0.16 and is PC-only, as every mod is. See the 1.0 mod compatibility tracker before you install one.
- Bigger send queue and rate: the default 32 KB queue at a 100% update rate allows up to 256 KB/s per player, against the 10 KB queue and 150 KB/s of vanilla 1.0.
- Compression: compresses world data, but only between machines that both run the mod.
- A connection buffer that its author says prevents data loss.
Tuning Better Networking
Open the Configuration Manager (F1) to adjust settings. Here's how to diagnose and fix specific issues:
| Problem | Diagnosis | Fix |
|---|---|---|
| NPCs are skipping/teleporting | Everyone's update rate too aggressive | Everyone: Set update rate to 75%, queue size to 48KB |
| A specific player is skipping | Their queue size is too large | That player: Reduce queue size to 32KB, then reduce update rate if still issues |
| Server has bandwidth to spare | The default queue is cautious | Server: try a queue size of 80KB (up to 640 KB/s per player) |
Compatibility Warning: its author says it is likely incompatible with other networking mods, so run one. A dedicated server only picks up changed settings after a restart.
The old manual fix (assembly_valheim.dll)
Guides from before 2022 edited three values in the game's assembly file. None of these fields exists in Valheim 1.0.17, so the edit has nothing to change: the limits now are the 10 KB send queue in the game code and the 150 KB/s Steam rate the server sets at start, which is exactly what the network mods change while the game runs. The old table, for reference only:
| Setting | Default Value | Recommended Value |
|---|---|---|
m_dataPerSec | 61,440 | 245,760 (4x Increase) |
m_dataPerSecLow | 30,720 | 122,880 |
m_minSendQueueSize | 2,048 | 8,192 |
Network Debugging (F2 and F5)
To see your current network health in-game:
- Press F5 to open the console (ensure
-consoleis in your Steam launch options). - Type
pingto see your latency to the server. - Press F2 for the network panel: data sent and received, the send queue, ping and frame rate. A connection sending close to 150 KB/s all the time, or a queue that keeps growing, is saturated.
Pro Tip: Most desync is caused by the player with the Worst Internet Connection entering a zone first. In Valheim, the first person in an area becomes the "Network Owner" for that zone. Always let the player with the best ping lead the way into the base.
General Network Optimization
Before or alongside Better Networking, apply these client-side optimizations:
1. Use Wired Ethernet
WiFi introduces latency and packet loss. Switching to a wired connection often eliminates desync entirely without any mods.
2. Optimize Steam Settings
- Open Steam → Settings → In-Game
- Change "In-game server browser: Max pings/minute" from 5000 to 250
3. Disable IPv6 (If Issues Persist)
Some networks have IPv6 routing issues. Try disabling IPv6 on your network adapter:
- Windows: Network Settings → Adapter Properties → Uncheck "Internet Protocol Version 6"
- Linux: Add
net.ipv6.conf.all.disable_ipv6=1to sysctl.conf
4. Disable Crossplay (Steam-Only Groups)
If all players are on Steam, disable crossplay for better performance. The PlayFab backend used for crossplay can introduce additional latency compared to pure Steam networking.
Ashlands Performance Warning
Players report more lag in the Ashlands than anywhere else: fights there involve many creatures, projectiles and fire effects at once, which is a lot for the area's owner to keep in sync.
Ashlands-Specific Tips:
- Keep the group together, so one player owns the area instead of several
- Better Networking is almost mandatory for Ashlands multiplayer
- Avoid building large bases in the Ashlands; build in the Meadows and portal in
- Expect some performance hits even with optimizations
Build without fear of the "Desync Devil." Host your Valheim server with Supercraft and switch on BepInEx and 1-click Thunderstore mods, a network mod included, from the panel.