How to Enable Parallel Light Updates in ScalableLux

ScalableLux ships with parallel light updates disabled by default, because the feature trades a bit of safety for raw throughput. If you are doing something like pre-generating a large world or running a server with many players spread across freshly loaded chunks, turning it on is the single biggest lever you have.

Finding the config

Open your instance's config folder and look for the ScalableLux config file (it may be a .json, .toml, or .properties file depending on your loader). Open it in any text editor. Look for an entry whose name references parallel light updates or threading. It is a boolean toggle — you flip it from off to on.

Applying and verifying

Save the file and fully restart the game or server. A world reload is not enough; the thread pool is created at startup. Once running, load a fresh area or trigger a large light change (breaking a roof over a big room works well) and watch your CPU usage. If multiple cores spike instead of one, parallel updates are active. If you see visual light glitches, flip the toggle back off — the default single-threaded path is the safer choice for normal play.