Minecraft server lag: diagnose TPS and MSPT with spark

Understand the measurements

• TPS measures the server’s tick rate, normally targeting 20 ticks per second.
• MSPT measures how long a tick takes to process. At 20 TPS, the average budget is 50 ms.
• Ping measures communication delay. Healthy tick rates do not fix an unstable connection.
• FPS measures frames rendered on the player’s computer. Shaders can reduce FPS while the server is healthy.

Ask whether everyone is affected. Record the location, player count and activity. Exploring fresh terrain at speed is a different workload from standing in a developed spawn area.

Capture a representative session

With the required permissions, run this in-game while the problem is occurring:

/spark profiler start --timeout 300

Continue the activity for the five-minute capture and open the report linked in the console. Paper also documents a targeted capture for slow ticks:

/spark profiler start --only-ticks-over 100 --timeout 300

The second example selects spikes over 100 ms. Keep a general capture as well; profiling an empty server can miss the issue completely. Check reports and logs for private information before sharing them publicly.

Interpret the context

Look for expensive main-thread work and inspect the surrounding call path. A plugin appearing in the report is a lead, not automatic proof that it is responsible. Compare spikes with saving, terrain generation and entity activity.

If tick performance stays healthy, compare a wired connection and another network. If only one player’s rendering suffers, temporarily reduce that client’s graphics settings. Avoid changing unrelated server files to address a local graphics problem.

Make one change and measure again

Use a test copy to disable a suspected plugin or repeat the activity away from a busy area. For generation spikes, consider preparing a limited world region. For entity load, identify the build responsible rather than deleting entities indiscriminately.

Capture another profile with a similar player count and workload. Record the original setting, change and outcome. Our Minecraft RAM guide covers memory sizing; profiling establishes whether memory is actually the limiting resource.

Decide whether hosting is the constraint

If a reasonable workload consistently exceeds the available resources, send the evidence to support. Compare CPU availability, memory, storage and location. Changing hosts cannot repair a faulty plugin or increase a player’s GPU performance. A measurable requirement is more useful than a promise of unlimited slots.

Frequently asked questions