Direct answer
Experience orbs are entities. Dense XP farms can create short bursts of orb updates, tracking and collection even when their mobs are processed efficiently.
How to check it
- Profile a representative XP farm while running and again immediately after it is stopped. Compare entity counts and collection behavior, not just visible particles.
- Record the original configuration or test conditions, capture a profile or a repeatable observation, and identify the affected world or player group.
- Make the measurement under the same player count and workload you will later use to verify the change.
What to change
Improve where and how orbs are collected. Spigot merge-radius.exp addresses the initial spawn merge on some versions; do not confuse it with continuous merging after spawn, and verify the current documented behavior.
Test player XP awards and orb collection carefully: merging behavior may affect user perception even if the total XP remains unchanged.
Software and version notes
Check the active version and generated configuration before copying paths or values. Different forks and mod loaders may implement this behavior differently.
This article is written for Paper / compatible servers. Configuration keys and defaults can move between versions. The source material checked for this page includes PaperMC spigot.yml reference. If your server is Folia, Leaf, Purpur, Fabric, Forge, NeoForge, or another fork/loader, do not assume a Paper-only setting exists or behaves identically.
Verify the result
Repeat the same test with the same software build, player count and world activity. Compare the targeted symptom and any spark measurements, then check that intended game mechanics still work. If the change does not produce a reproducible improvement, revert to the recorded baseline.