Optimizing your Hytale server (lag, etc.)

The term “lag” refers to response delays or slowdowns encountered by players on a server. A “server lag spike” is a sudden and temporary increase in this latency, often due to a momentary overload. To ensure optimized server performance, it is crucial to identify and mitigate these sources of slowdown.

The main causes of lag

Lag can stem from several interdependent factors:

• Insufficient hardware resources: CPU, RAM, or even storage speed.
• Inappropriate server configuration: Game settings, view distance, entity management.
• Network issues: Unstable internet connection, poorly configured firewall, congestion.
• Software overload: Too many players, entities, or resource-heavy mods.

Hardware and operating system optimization

The infrastructure your server relies on is the first line of defense against lag.

Allocating adequate RAM

Random Access Memory (RAM) is an essential element for a Hytale server. Being a voxel sandbox game, it is particularly demanding on CPU and RAM.

• Small server (approx. 1-5 players): 4 GB of RAM is generally sufficient.
• Medium server (5-15 players): Aim for 6 to 8 GB of RAM for a comfortable experience.
• Large server / public server (15+ players): Plan for 10 to 16 GB of RAM to manage a high number of concurrent players and loaded areas.

Tip: Hytale runs on Java 25. For dedicated deployments, use the -Xmx option of the OpenJDK 64-bit virtual machine to set the maximum RAM limit the server can use.

For example, java -Xms8G -Xmx8G -jar HytaleServer.jar will allocate 8 GB of RAM. Excessive memory pressure due to insufficient allocation can lead to increased CPU usage caused by Java “garbage collection”.

Choosing the right processor and GPU

• Processor (CPU): A powerful CPU with many cores is crucial, as Hytale heavily taxes the processor for world calculations, NPC management, and entity counts. Each world runs on its own main thread, offloading parallel work to a shared thread pool.
• Graphics Card (GPU): Although less critical for a dedicated server without a graphical display, a good graphics card on the host machine can help offload certain tasks. VRAM (video memory) is used for “texture atlases” and world geometry, and a high view distance will increase this usage.
• Storage: A SSD (NVMe is recommended) with at least 20 GB of free space is strongly advised for optimal world loading performance.

Network and connection

Hytale uses the QUIC protocol over UDP (User Datagram Protocol) for client-server communication, not traditional TCP.

• Port opening: Ensure that UDP port 5520 (or the one you configured via --bind) is open on your firewall and that port forwarding is correctly configured on your router if your server is behind a NAT. TCP is not required.
• Symmetric NAT: Symmetric NAT configurations (common on mobile networks) can cause issues. In this case, a VPS or dedicated server is preferable.
• Client-side prediction: Hytale integrates “client-side prediction” to minimize perceived lag, where the client anticipates the game state based on server data.

Software optimization and server configuration

Once the hardware is optimized, fine-tune your Hytale server settings for maximum fluidity.

View distance

View distance is the primary factor in RAM and CPU usage. It is the radius around the player that is visible, loaded, and simulated. Doubling the view distance quadruples the amount of world to load and simulate.

• Hytale default value: 384 blocks (equivalent to about 24 Minecraft chunks, compared to 10 by default on Minecraft).
• Recommendation: Limit the maximum view distance to 12 chunks (384 blocks) for an optimal balance between performance and immersion. For less powerful machines, a lower value, like 192 blocks, is recommended. Adjust this value based on your player count and gameplay style.

Keeping your server up to date

Regular updates are essential to benefit from optimizations, bug fixes, and performance improvements. The Hytale protocol uses hashing to verify client-server compatibility; thus, an unupdated “current server version” may prevent players from connecting.

• Update methods: Use the Hytale Downloader CLI tool or copy files from the launcher.
• Backups: Always perform a full backup of your server data before any update.

Managing mods and plugins

While mods enrich Hytale, an excess of content or poorly optimized plugins can be a major source of lag.

• Performance impact: Voluminous content packs, complex server logic, or extended view distances can tax the CPU and GPU more heavily.
• Optimization plugins: Some plugins, like Nitrado:PerformanceSaver, can dynamically limit view distance based on resource usage. Choose your plugins wisely and test their impact.
• “Early plugins”: Be extremely cautious with “early plugins” as they execute before the server starts and can affect game stability.

Monitoring and diagnostics

Server log files are your best allies for identifying performance issues.

Log location:

• Windows: %APPDATA%\Hytale\UserData\Saves\[world]\logs
• macOS: ~/Library/Application Support/Hytale/UserData\Saves\[world]\logs
• Linux: $XDG_DATA_HOME/Hytale/UserData\Saves\[world]\logs or ~/.local/share/Hytale/UserData\Saves\[world]\logs

Log analysis:

Regularly examine “Hytale server logs” for “critical severity” (SEVERE) messages, errors, or warnings. They can reveal bottlenecks or conflicts between plugins.

Multi-server architecture: beyond a single world

For large communities or complex networks, a “multi-server architecture” can be considered to distribute the load and improve overall performance.

• Proxy servers and load balancing: “Proxy servers” and load balancing systems can distribute network traffic across multiple Hytale servers, avoiding latency spikes on a single server.
• Player transfer and redirection: Hytale supports native mechanisms to redirect players between servers, allowing players to be switched to less loaded servers or those specific to a mini-game.