UsefulMods VS lazydfu

There's tons of mods that do what Optifine did now. https://github.com/TheUsefulLists/UsefulMods

You can try Java tweaks - https://github.com/brucethemoose/Minecraft-Performance-Flags-Benchmarks or performance mods - https://github.com/TheUsefulLists/UsefulMods

Reference this list of performance mods, find your version, and ensure you're using as many as possible (as long as 2 don't conflict.)

Just an FYI, that list has been archived and is no longer being maintained. Use this instead: https://github.com/TheUsefulLists/UsefulMods

From LazyDFU's github repo:

1) LazyDFU: Compiled DFU rules afterwards. 2) EntityCulling: Doesn't render entities that you can't see 3) NoFade: This isn't exactly a performance mod, but fading sometimes makes my game crash, so I use this. 4) NotEnoughCrashes: Again, not a performance mod, but makes crashes much easier to handle. 5) SmoothBoot: Makes Minecraft not hog too many resources when starting up 6) SodiumExtra: Basically adds more options to Sodium. 7) Hydrogen: idk how to describe this (I no longer don't use this as 1.18 hasn't released yet, but I'll this in anyway). 8) C2ME: Improves chunk performance. 9) Enchanced Block Entities: Improves rendering of block entities. Note that this only really shows effect when you're in an area with tons block entities (eg. your storage basement)

LazyDFu v0.1.2

I would suggest you to use Sodium or Iris - Overall Performance Improvement / Iris If You Wanna Use Shaders Too Lithium - Improve CPU Usage LazyDFU - Launch Game Faster Phosphor - Improve Light Engine Hydrogen - Reduce Memory Usage

I'd recommend checking out some of the mods in the fabulously optimized modpack. Most notably I'd recommend LazyDFU, No Fade, and Smooth Boot as they're most applicable to the problem you're describing.

(Experimental) Lazydfu ( astei/lazydfu )

You could try installing Hydrogen and LazyDFU t see if they do anything for this. Hydrogen will reduce Minecraft's Memory usage, which should help with the GC pauses slightly. LazyDFU will improve startup times and reduce the massive amount of garbage from DataFixerUpper during startup (Mojang's backwards compatibility system), which might also improve things during gameplay as well.