Re-Console comes with a lot of mods, but if you'd like to modify it, there's a bunch of mods that I recommend!

Additional Performance Mods

Concurrent Chunk Management Engine

C2ME is a mod designed to improve chunk performance using multi-threading. It can improve performance on some systems, but on low end it can be detrimental due to increased resource usage.

FastQuit

FastQuit is a mod that can save your worlds in the background! Although on Re-Console, and all Legacy4J modpacks as a whole, it may cause issues regarding world corruption. Use at your own risk!

Faster Random

Faster Random may slightly improve world generation performance.

Very Many Players

VMP is an experimental mod which can improve serversided performance. It is already included in RCSS (Re-Console Server Software) by default, but it may have marginal clientside performance improvements.

Other ways to improve performance

Reduce Resolution on MacOS

If you're on a Mac with a Retina display, it is heavily recommended to enter the Sodium options menu (Mods>Minecraft>Video Settings>Extras), and enable the "half resolution" option under the "Extra" tab. You will have to restart the game after turning this on! This can boost FPS from ~100 to >200, based on others testing.

If you're on versions between 0.8.0 beta 12 and 14, you can also use Resolution Control 3 to do a similar thing.

Adjust Memory (RAM) allocation

Allocating more memory to Minecraft may increase performance very significantly, as seen in Forestplayz review of Re-Console, that suffered from performance issues due to low memory allocation.

However, setting it too high can cause issues as well. It may start to slow down your game if you go above 8GB (8192mb), due to Java not being able to handle that high of an allocation properly.

If you have a low amount of memory installed, do make sure to keep enough memory for your system. A good rule of thumb is to allocate 2-6 GB (2048-6144 MB) to Re-Console depending on your configuration, settings, and system hardware. Other modpacks may require more RAM allocated, such as William's Console: Revisited, which recommends 8GB (8192mb) of memory to be allocated to Minecraft.

Never set your allocated memory to the same amount as your installed memory.