BetterNetworking PC

Better Networking PC 2.3.5 (Valheim 1.0.x)

valheim-better-networking-pc is an unofficial fork of

Better Networking

by CW_Jesse, updated to run on Valheim 1.0. Built

against the l-1.0.7 assemblies (network version 39) and verified against l-1.0.12,

l-1.0.14 and l-1.0.16 (network version 40), which it has run on through each

auto-update. Credit for the original mod goes to CW_Jesse and its contributors; this

repository carries the changes needed to keep it working on the current game version, plus

the portal fixes described below.

PC only. "PC" in the name is the platform: this is a BepInEx mod for the PC (Steam)

version of Valheim and for dedicated servers. It cannot be installed on Xbox or

PlayStation, because consoles cannot load mods. It has only been run and measured on Steam

with crossplay off.

Up to 2.3.4 this fork shipped under the original name, as CW_Jesse.BetterNetworking.dll.

From 2.3.5 it is Better Networking PC, BetterNetworkingPC.dll. See

Compatibility with the old name.

No official build claims 1.0 support: upstream 2.3.2 targets 0.217.28, and the 2.3.3 fork

targets 0.221.4.

What the mod does

Vanilla Valheim caps how fast a machine sends world data to each peer. On a busy server

every player flatlines at the same ceiling, which is what the lag during group play

actually is. The mod raises the send queue (10 KB to 32 KB) and Steam's send rate

(150 KB/s to a 256 KB/s minimum and 1024 KB/s maximum), and adds zstd compression between

machines that both run it.

Measured results

From one live server between 2026-09-11 and 2026-09-13: 10 distinct players on home

connections, crossplay off, direct Steam sockets. Traffic was captured with tcpdump on

the server and binned per player per second; figures are p50 / p90 / max of those

one-second bins, per player, one direction.

Only compare captures taken with players clustered together. Valheim only sends a

player what is near them, so a scattered group produces about 1 KB/s each in vanilla too.

Mixing the two states makes the mod look broken when it is not.

The problem: vanilla clamps every player at one number

Server to each player, no mod, clustered:

| Hardware | Players | p50 | p90 | max |

|---|---|---|---|---|

| i7-9700 | 7 | 37-42 | 43-44 | 43-45 KB/s |

| i9-9900K | 5 | 62-63 | 63-64 | 64-80 KB/s |

Several players stopping dead at the same number is a cap, not demand. Neither machine was

short of anything: CPU 15-30% of one core, 1.5 GB resident, and the uplink peaked at

4.7 Mbit/s on a line proven to carry 121 Mbit/s.

With the mod on the server

Same measurement, one figure per player in the capture (i7-9700):

| Players | p50 | p90 | max |

|---|---|---|---|

| 4 | 34, 103, 109, 126 | 50, 127, 133, 141 | 54, 147, 172, 180 KB/s |

| 6 | 12-58 | 25-94 | 53-150 KB/s |

| 8 | 5-65 | 29-90 | 51-135 KB/s |

Roughly twice the sustained rate and three times the peak, and the flat clamp is gone:

rates now move with what is happening instead of stopping at one number. Totals through the

server were 705 KB/s in and 281 KB/s out at 8 players, about 2.2 Mbit/s of upload.

Server load did not change meaningfully. Valheim's main thread, the one that saturates

first, sat at 29% of one core with 8 players (35% max) against 8% idle, and memory went

from 1.52 GB to 1.76 GB.

What limits it next: unmodded clients

With 7-8 players on, the server peaked at 132-136 KB/s per player against a queue allowing

roughly 640 KB/s, so the server had stopped being the constraint. The vanilla clients had

not: each sat at 113-138 KB/s, which is vanilla's 150 KB/s send rate once overhead is

counted. Valheim has the client nearest an area simulate it, so in a group fight one player

uploads every monster's state for everyone and hits that cap. This is why fights can still

lag after a server-side fix.

With the mod on one client and seven still vanilla, on the same server and session:

| Connection | To server | From server |

|---|---|---|

| Modded client | 26-29 KB/s | 15-44 KB/s |

| The 7 vanilla c