7 Days to Die Server Optimization Guide
The settings that actually reduce 7 Days to Die server lag, with their real names, defaults and ranges.
Start Here
7 Days to Die runs its main loop on a single thread. Clock speed matters more than core count, and there is a ceiling on what any amount of hardware will do for a very busy server.
Every setting below is in the Settings tab. None of them is marked restart-required, which means saving one does NOT restart your server for you - the game reads its config at startup, so restart once you are done changing things.
The Overview tab has a live CPU and memory graph. Watch it during a horde night; that is when the numbers mean something.
Zombie and Animal Counts
Zombies are the biggest cost. Each one needs pathfinding, AI and physics.
Max Spawned Zombies (Performance, default 64, range 0-500) - the server-wide cap on zombies alive at once. Lowering it to 40 or 32 is the single most effective change on a struggling server, and it caps horde night as well as ordinary spawns.
Max Spawned Animals (Performance, default 50, range 0-200) - the same for wildlife. Worth halving on a busy server.
The blood moon horde size itself is part of the Sandbox Code, not a separate setting. Lowering the cap trims the horde down to fit; changing the code stops the server being asked for a horde that size in the first place. See Configuring Blood Moons.
View Distance and Chunks
Max Allowed View Distance (Performance, default 12, range 4-20) - a cap on how far each client may render. Lower it to 8 and the server loads fewer chunks per player, which cuts both CPU and memory.
Max Queued Mesh Layers (Performance, default 1000, range 100-5000) - how much chunk mesh work may be queued at once. Lowering it uses less memory but makes chunks appear more slowly.
Max Uncovered Map Chunks Per Player (World, default 131072) - how much explored map one player may accumulate. Relevant on a long-running server with heavy explorers.
Max Chunk Age (World, default -1) - in-game days before an unvisited, unclaimed chunk resets to how it generated. Setting it to something like 30 keeps an old world from accumulating forever. -1 disables it.
Dynamic Mesh
Dynamic Mesh is what lets structures deform and collapse. It is expensive, and there are four settings for it under Performance.
Dynamic Mesh Enabled (default on) - turning it off is the biggest single saving available, at the cost of the destruction physics players expect.
Dynamic Mesh Land Claim Only (default on) - keeps the work inside player claims rather than across the whole map. Leave this on.
Dynamic Mesh Land Claim Buffer (default 3, range 0-20) - how many chunks around a claim are included. Lower it before turning Dynamic Mesh off entirely.
Dynamic Mesh Max Item Cache (default 3, range 1-20) - how many mesh items are processed at once.
Other Levers
Maximum Players (Basic, default 8, range 1-64) - restart-required, so saving it restarts the server. 7 Days to Die does not scale gracefully with player count; if you are running 16 or more and struggling, two servers will feel better than one.
Max World Transfer Speed KiB/s (Performance, default 512, range 0-10240) - the rate world files are pushed to a joining client. Raising it makes joins faster and briefly costs bandwidth.
Easy Anti-Cheat (Basic, default on) - turning it off saves some CPU, and most mods need it off. It has a real cost though: EAC is required for crossplay, so turning it off means console and Epic players can no longer join. Only do it on a Steam-PC community you trust.
World Generation Size (World, new-world-only) - a smaller world has fewer chunks to touch. This only applies to a world you have not generated yet.
Memory and Hardware
7 Days to Die is memory-hungry. The reference figure the platform uses for this game is 4 GB, 2 CPU cores and 20 GB of disk, and a busy or heavily modded server wants more than the floor.
There is no RAM allocation setting for 7 Days to Die in the panel, and there is nothing to tune in a startup script - the game is not a JVM and takes no heap arguments. If your server needs more resources than it has, that is a plan question, not a settings question. Open a ticket.
What you can do from Settings is reduce demand: zombie cap, view distance, dynamic mesh, world size.
Common Lag Causes
Blood moons - the most CPU-intensive event in the game. Lower Max Spawned Zombies first.
Large bases - a lot of blocks, especially powered ones, doors and hatches, is expensive. Dynamic Mesh Land Claim Only concentrates the cost where the bases are; keeping bases sane is a community rule rather than a setting.
High player count - see above. The engine, not the host, is the limit.
Old worlds - accumulated explored chunks, dropped items and entities. Max Chunk Age helps; a periodic wipe helps more.
Mods - overhaul packs cost significant CPU and memory. Test one on a second server before putting it on a live community.
A very long uptime - set an automatic restart on the Admin tab. It fires only when nobody is connected, so it costs your players nothing.