Direct answer

merge-radius.item controls the distance in blocks at which compatible dropped-item entities may combine. A larger radius can reduce item-entity counts, but may change where items combine, affecting collectors and farm behavior.

How to check it

  1. Reproduce a high-item scenario: a farm, explosion or large item drop. Record item-entity counts and spark profiler samples.
  2. Inspect world-settings.default.merge-radius.item in spigot.yml and any per-world setting.
  3. Check whether your bottleneck is actually dropped items, rather than hoppers or chunk loading.

What to change

Start from the generated configuration. The PaperMC Spigot reference shows an item default of 0.5 blocks. If profiling justifies adjustment, change one value and test in an isolated area. Do not assume a large radius is harmless in sorting systems.

# spigot.yml:
world-settings:
  default:
    merge-radius:
      item: 0.5
      exp: -1
Different settings

item controls item merges; exp has a separate initial-XP-spawn behavior. Entity activation range and hopper transfer timing are unrelated settings.

Software and version notes

Documented for Spigot-style config on Paper and compatible servers. Always compare against your own generated YAML and server release. Modded servers need loader-specific documentation.

Verify the result

Compare item counts, MSPT and actual farm pickup/sorting behavior under the same load. Revert if merging changes item routing or provides no measurable benefit.

References