Direct answer
Rapid observer clocks create repeated block updates. They can also trigger downstream pistons, dispensers or hoppers, so the expensive part may be the attached machine rather than the observer.
How to check it
- Disable one clock or copy the machine to a staging world, then profile block updates while running it at the normal frequency.
- 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
Use an on/off switch, event-driven pulses or lower operating frequency where the farm permits. Count affected blocks and pistons; do not claim that replacing observers always reduces cost.
Confirm the build still performs required operations and behaves the same after a chunk unload/reload.
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 profiling guide. 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.