Minecraft Server Lag Explained | Causes, TPS Drops & Fixes
Stop guessing. Calculate the optimal settings based on your hardware.
You place a block, and it disappears. You eat a steak, but your hunger bar doesn’t move. You try to hit a zombie, but it freezes and then teleports behind you.
Lag is the silent killer of Minecraft servers.
But here is the hard truth: Throwing more RAM at the problem rarely fixes it. You can have 64GB of RAM allocated, but if your Simulation Distance is set to 32, your server will still crash.
Minecraft lag isn’t magic; it’s math. It comes down to Ticks Per Second (TPS) and Milliseconds Per Tick (MSPT). Understanding the relationship between these numbers is the only way to run a smooth server for your friends.
In this guide, part of our Minecraft Tools Collection, we will break down the technical settings that actually matter.
The Golden Rule: 20 Ticks Per Second (TPS)
Before we touch a single setting, you need to understand the engine. Minecraft runs on a loop that repeats 20 times every second.
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1 Second = 20 Ticks.
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1 Tick = 50 Milliseconds (MSPT).
Every tick, the server has to calculate everything: crop growth, mob movement, redstone updates, and water flow. If the server can do all that math in less than 50ms, your game runs at 20 TPS (Green/Perfect).
The Lag Spiral: If the math takes 60ms (because you have 500 villagers in one hole), the server falls behind. It skips ticks. Your TPS drops to 15. The game feels “slow-motion.”
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20 TPS: Perfect.
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15 TPS: Noticeable delay on eating/breaking.
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< 10 TPS: Unplayable. Mobs teleport.
Simulation Distance vs. Render Distance: The Big Confusion
This is the #1 topic where admins get confused. In older versions of Minecraft, these were the same setting. Now, they are separate, and knowing the difference saves your CPU.
1. Render Distance (The “Visual” Setting)
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Definition: How many chunks away the player can see.
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Who does the work? The Client (The player’s PC).
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Server Impact: Low to Medium. The server just has to send the chunk data once.
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Verdict: You can set this high (10-16) if your players have good internet connections. It makes the world look pretty.
2. Simulation Distance (The “Math” Setting)
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Definition: How many chunks away the server calculates physics.
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Who does the work? The Server (CPU).
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Server Impact: MASSIVE.
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The Math: Chunks load in a square radius.
Sim Distance 5 = $(5 \times 2 + 1)^2$ = 121 Active Chunks per player.
Sim Distance 10 = $(10 \times 2 + 1)^2$ = 441 Active Chunks per player.
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Verdict: Increasing Sim Distance from 5 to 10 quadruples (4x) the CPU load.
The Strategy: Keep Render Distance High (12-16) so players can see far away mountains. Keep Simulation Distance Low (4-6). Do you really need a sheep to eat grass 10 chunks away? No. You only need physics happening close to the player.
The “Paper.yml” Secret Sauce
If you are running a server on “Vanilla” Minecraft (the official jar file), stop immediately. Switch to PaperMC or Purpur. These are optimized server forks that allow you to edit the paper.yml file.
Here are the three mathematical changes that reduce lag by 50%:
1. Mob Soft Caps (Entity Cramming)
By default, Minecraft allows huge numbers of mobs. In paper.yml, find entity-activation-range.
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Default: Monsters activate 32 blocks away.
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Optimization: Reduce
monstersto 24 or 16. -
Why? If a zombie is 30 blocks away, the player likely isn’t fighting it. Why waste CPU calculating its pathfinding?
2. Hopper Checks
Hoppers are notoriously laggy because they check for items 20 times a second.
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Setting:
hopper-transferandhopper-check. -
Optimization: Increase
hopper-checkto 2 or 3. -
Result: The hopper checks every 3 ticks instead of every 1 tick. This cuts hopper lag by 66% with almost zero noticeable difference in gameplay.
3. Grass Spread
Does grass really need to grow instantly?
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Setting:
random-tick-speed. -
Default: 3.
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Optimization: Keep it at 3, but ensure you aren’t running modded items that accelerate this. If TPS drops, temporarily setting this to 0 stops all crop growth and fire spread, giving the server time to recover.
Need a custom config file? We are working on a Paper.yml Config Generator to generate these files for you instantly.
Client-Side Lag (FPS) vs. Server Lag (TPS)
Don’t confuse the two.
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FPS Lag (Frames Per Second): The game looks like a slideshow.
Cause: Your graphics card (GPU) or weak CPU.
Fix: Install Sodium or Optifine. Lower graphics settings. The server admin cannot fix this for you.
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TPS Lag (Ticks Per Second): The game looks smooth (60 FPS), but blocks reappear after you break them.
Cause: The server CPU is overloaded.
Fix: Lower Simulation Distance, kill excess mobs, restart server.
FAQ: Lag & Optimization
How much RAM do I really need?
For a vanilla/Paper server with 5-10 friends, 4GB to 6GB is usually the “sweet spot.” Allocating too much RAM (like 32GB) can actually cause lag due to something called “Garbage Collection spikes” (Java trying to clean up too much memory at once).
Does “ClearLagg” actually work?
Plugins that delete ground items (like ClearLagg) are mostly a placebo in 2025. Modern items on the ground barely cause lag compared to mob AI (pathfinding). You are better off optimizing your spigot.yml mob caps than deleting dropped cobblestone.
What is the best startup flag?
Using “Aikar’s Flags” is the industry standard for Java Garbage Collection. It smoothens out the memory cleaning process so your server doesn’t freeze every 10 minutes.
Conclusion
Running a lag-free server isn’t about buying the most expensive hosting plan. It is about understanding the math of Simulation Distance.
By keeping your physics calculation radius small (Sim Distance 4-6) and letting players see far (Render Distance 10+), you get the best of both worlds: a beautiful view with a stable 20 TPS.
Next Steps:
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Use the Lag Calculator at the top of this page to check your settings.
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If you are building a large farm that might cause lag, use our Minecraft Block Area Calculator to plan it efficiently before you place a single block.
Is your server running smoothly? Let us know your TPS in the comments!
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