RaphiMC
FPS is stuck at 5 on arch linux, but not on windows.
So i often use FO as my optimization pack of choice, and this mod is causing performance to shit on 1.20.2, 1.19 and probably other versions (not tested). But it runs fine on windows for some reason. System specifications are: AMD FX-6300 Radeon HD 6570 6GB DDR3 RAM
No errors come up in the console, it just runs beyond awful.
Please install spark on the client (https://spark.lucko.me/download) and start profiling when you are ingame and your game lags: /sparkc profiler start --thread * --timeout 30. After 30 seconds it will finish and give you a link to the result. Send the link here so I can take a look at the lag source.
Here it is: https://spark.lucko.me/fPeLr6EYrG Sorry i took so long to respond in the first place.
The profiling results don't tell much sadly. From what I saw I would say this is caused by external source (for example your system / system configuration). Minecraft seems to be spending a lot of time getting blocks from the chunks, which ImmediatelyFast doesn't even touch. Maybe you can play around with disabling some of the options in the immediatelyfast.json config file and see if that resolves the issue
Just to throw in my own experience: The mod hasn't caused any issues performance-wise (that I can tell) on Manjaro, and that's including occasional shaders.
My specs are quite a bit different though Ryzen 7900X Radeon 6900XT
