Performance & Lag
27 guidesDiagnosing and fixing TPS drops, lag spikes, memory pressure and slow chunk loading on a Minecraft server.
Start by working out which problem you have, because two very different things get called lag. Low TPS means the server cannot finish its work inside a tick. High ping means packets are slow to reach you. They have separate causes and separate fixes, so telling TPS lag from ping lag is the first step.
If it is genuinely the server, measure rather than guess. A timings or spark report names the mod, plugin or task eating the tick, and this guide separates CPU, RAM, ping and mod causes. Two changes fix most servers: pre-generating the world with Chunky so players are not generating terrain as they explore, and lowering view-distance and simulation-distance.
Worth knowing before buying a bigger plan: Minecraft's main loop is single-threaded, so more memory does not make a tick shorter. That is why upgrading RAM or vCores does not always fix lag, and why rising memory is usually normal rather than a leak.
- Can I limit or reduce RAM usage without upgrading?
- Can I upgrade RAM, vCores, or disk later, after I've bought?
- Can I use custom startup flags (MaxRAMPercentage, -nogui, velocity flags, OpenJ9)?
- Chunks stop loading / render slowly / there's a map border far from spawn — how do I fix it?
- Geyser causes very high RAM/CPU — what's the solution?
- High CPU usage (150–250%+) is causing lag — cause and fix?
- How do I add or upgrade vCores, and can I trade RAM for cores?
- How do I change view-distance / simulation-distance?
- How do I get and read a timings or spark report?
- How do I monitor RAM and CPU usage?
- How do I pre-generate the world with Chunky to reduce lag?
- How do I tell server lag (TPS/MSPT) from ping lag?
- Is a datapack, lag machine, or mob spawning causing my high CPU?
- Is my lag caused by the server being far from my players' region?
- Is my lag from CPU, RAM, ping, mods, or plugins — how do I tell?
- My RAM keeps rising and never drops (memory leak) — is that normal? How do I fix it?
- My server is lagging (low TPS) — how do I improve performance?
- My world or a chunk is corrupted after a mod/version change — how do I recover?
- Should Xms and Xmx be equal? What values?
- What RAM buffer / minimum RAM values should I use?
- When I try to upgrade, only RAM options show (not vCores) — why?
- Where do I set RAM buffer, minimum RAM, Xms/Xmx, and what values?
- Which FTP/FTPS client do you recommend?
- Which optimization flags (Aikar's) should I use?
- Why does my server show less RAM than I paid for (e.g. 4GB shows as 2GB)?
- Why does my server use so much RAM even when idle or with few players?
- Will upgrading RAM / vCores / to Ultimate actually fix my lag?
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