Slow LOD generation

[MagicJinn]

Both these benchmarks were performed with Java 23, 16 render distance (and 16 simulation distance, set independently in the modern version), no other mods, vanilla terrain, CPU preset 5 (IPFTWCPU), LOD Distance 96, 16GB of RAM allocated

1.12.2: 40 minutes until complete
1.21.10: 10 minutes until complete

I am aware that this is in the readme, but I wanted to open this issue to make sure the performance discrepancy remains visible and tracked

(Just wanted to mention that I REALLY appreciate this mod existing, and I just want it to be as good as it can be!)

[Karnatour]

This is caused by 1.12.2 world gen being bad compared to modern. Set in 1.21.10 world generation type to INTERNAL_SERVER (this is only option what 1.12.2 have implemented) to make the benchmark "fair"

There is nothing I can do until someone rewrite 1.12.2 world generation to make it off thread

[MagicJinn]

Well strictly speaking, the benchmark is fair, since we are benchmarking LOD generator results, not minecraft world generation speed.

There is nothing I can do until someone rewrite 1.12.2 world generation to make it off thread

When you say this, are you refering to vanilla worldgen? Or Distant Horizons world gen. I completely understand that re-implementing the modern distant generation code in 1.12.2 is an extremely daunting task, but I think we should keep the option on the table.

[Karnatour]

1. Did you created fresh world or did you created world visit all chunks manually and then install DH ?
   If not then DH works like this: Ask world generator to generate chunk data(slowest part) -> create LOD from this.

INTERNAL_SERVER force loads the chunk as if player would visit it and save it into game files.
FEATURES does not save the chunk into game files -> being faster.

1.12.2 DH has ONLY INTERNAL_SERVER, since you would have to rewrite 1.12.2 Minecraft world generation to implement FEATURES (Modern DH does it with 0 changes to Minecraft worldgen afaik)
1.13+ Has FEATURES and DH can request the chunk data on multiple threads (being a lot faster) Because Mojang did big changes to the world generation system

In 1.12.2 all chunk generation must run on main thread resulting in destroying TPS

So to make the benchmark fair you must set INTERNAL_SERVER in 1.20.1 you will see it will be a lot slower than FEATURES
Better explanation is on DH discord under !generators command

Also 1.12.2 is on old core version of DH right now (modern core could have optimized LOD creation)

If you would want to compare LOD generator result you MUST have all chunks pre-generated

[MagicJinn]

Well strictly speaking, the benchmark is fair, since we are benchmarking LOD generator results, not minecraft world generation speed.
If you would want to compare LOD generator result you MUST have all chunks pre-generated

What I meant with this is that to the end user, the speed of the generator is what counts, no matter what it is set to. The average user will only boot up the game and notice distant generation is slower.

Thanks for the technical rundown. I did know a couple of these things, but there's a decent amount I didn't know about at all.

And yes I did create fresh worlds for each benchmark.