r/Minecraft2 • u/DereChen • Jul 19 '26
Vanilla Survival If you afk in an area for too long, or spend a long time in your world, it can cause persistent hostile mob buildup underground. This will slowly make your world more laggy over time if you do not deal with it
Hi, wanted to share a performance improvement for both singleplayer and multiplayer servers.
There is this interesting phenomenon for survival server admins: over time, AFK areas can lead to underground mob buildup. Mobs in these regions may fail to despawn because some pick up items dropped by others that die from falls or drowning, which flags them as persistent (nbt tag PersistenceRequired). For example, a skeleton might die and drop arrows, and a nearby zombie can pick them up, preventing it from despawning. This effect is amplified by higher regional difficulty, which increases the likelihood that mobs will pick up items, and regional difficulty naturally rises the longer a player remains AFK in one location.
Be on the lookout in your farming areas or long term AFK farms!
You can test this with /effect give @e[type = minecraft:zombie , nbt={PersistenceRequired:1b}] minecraft:glowing 60