I am playing Hypixel skyblock and when I open a custom GUI, for example the auction house, the fps will drop to an unplayable state. I think it's due to the custom items and lores having lots of data being scanned by the mod to generate custom item selection, since a normal chest with only few custom items does not lag. I can confirm its the mod because I removed the mod and it went back to normal fps when opening such GUIs.

I also found these as well: sp614x/optifine#3844 sp614x/optifine#3252

There is a cache length slider in the mod's config which raising should help with this. Though it will still come down to the size of the resourcepack used and the specs of your pc.

Does it need to invalidate the entire CIT cache every n milliseconds? Surely there is a way to watch for NBT updates instead...

Does it need to invalidate the entire CIT cache every n milliseconds? Surely there is a way to watch for NBT updates instead...

Very intentional, there are changes planned that are not reliant on the nbt changing at all, the cache has to be invalidated in case these conditions are checked with different results. If you want to have it not invalidate until the nbt changes you can just max out the cache length(or set it to max value in the config json)

Does it need to invalidate the entire CIT cache every n milliseconds? Surely there is a way to watch for NBT updates instead...

Very intentional, there are changes planned that are not reliant on the nbt changing at all, the cache has to be invalidated in case these conditions are checked with different results. If you want to have it not invalidate until the nbt changes you can just max out the cache length(or set it to max value in the config json)

I have the same problem with 1.20.1
https://youtu.be/5qc8y9BYTh8

Turns out that the CIT parsing is incredibly slow in some cases, throwing and catching (and ignoring) thousands of errors per tick. I fixed this issue and improved performance slightly in PR #311, with screenshots included.