tic-tacs VS phosphor-fabric

Starlight performs substantially better than phosphor and greatly speeds up terrain generation. Krypton for networking performance. C2ME or tic-tacs (both aim to do the same thing and are not mutually compatible) greatly improve world loading and terrain generation but are experimental and, in my experience, not compatible with a lot of other mods. Dimensional Threading puts each dimension on a separate thread, but also tends to not be very compatible with other mods. FerriteCore aims to reduce ram usage. This page has a whole list of mods.

Could also pregenerate your world with chunky. To make it quicker add Starlight, Lithium, tic-tacs(This might be incompatible with some worldgen mods, but it massively speeds up terrain gen speeds if it works), and Carpet(use the "/tick freeze" command to freeze the game so there's more resources for terrain gen). Then switch to a paper style Tuinity server and set the worldborder to keep people from moving past pregenerated chunks.

Tic-Tacs for world loading

I would recommend a fabric server running krypton, lithium, starlight, tic-tacs, hydrogen, and ferritecore. Those mods are geared towards optimizing chunk generation and loading while having 0 impact on vanilla game behavior (the last two are geared for reducing ram usage). Of all the performance mods I've messed around with, those are the ones that I would recommend most. You could also add carpet and set it up to add tps to the tab list if you want to easily see that number.

tic-tacs is an absolute must as it dramatically improves chunk load times

Also try Tic-tacs (can cause some issues).

And also run Tic-TACS which replaces Minecraft's clunky chunk loading engine for a multi-threaded awesomeness. This is the most experimental of the bunch, and the least recommended for any kinds of critical usage.

tic-tacs

Phosphor (another optimization mod by the Sodium devs, targeting the built-in lighting system)

Sodium Phosphor Lithium also get iris but I don't have download link

There’s lots of lightweight shader packs designed for low-end PCs. For an optimized, smooth shader experience I’d recommend installing Fabric, Sodium, Lithium, Phosphor, and Iris Shaders.

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

Low performance is to be expected with your config. You can try to install these performance mods for minecraft : * Iris that contains Sodium * Sodium, don't use it with iris, it already has sodium. * Lithium * Phosphor

Lithium is only for Fabric. There's also Phosphor to improve lighting performance.

You can get better performance and retain vanilla features by using Fabric with phosphor and lithium.

for newer versions Sodium+Lithium+Phosphor (+aditionally hydrogen)

Please use the Randon World Format for it uses less RAM and uses less file space and please use the Lithium Lighting Engine for the same reason.