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. Most are not 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 exceptions are called out where they come up.
The Resource Usage card on the Overview tab shows the server's current CPU and memory use. It is a live reading, not a graph, and it keeps no history. Check 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.