This is a lightweight mod project which hugely improves performance and blocklag.

Can be installed on either side, does not have to be on both. On client side it affects ssp performance and on serverside smp performance. Feel free to use it in any modpack

You can support my mods development by supporting me on my patreon below! You'll also find pre-release versions there for early access.(1.16 1&2 atm)

Most notable features:

 All features are configurable and can be tweaked/enabled/disabled in the config. 

Less AI overhead

AI's no longer spent like half their time deciding which task they should run

Multithreading of entity collisions and pathing

The expensive parts of entity updates, collisions pathing and movement are faster and happen are multithreaded.

Load balancing for AI/Entities, Tileentities and Events

Load balancing is a more invasive mechanic to throttle down lag offenders, it may affect functionality of other mods but only becomes active if your game is lagging already. It works by checking the server's tps regularly and if it is below the threshold in the config load-balancing becomes active. Then it starts to profile AI/Entities, Tileentities and Events to determine who is causing most lag and throttles down their updates in relation to the lag those sources cause. This is mainly a functionality to keep your game playable while some specific lag sources would normally bring it to its knee's.

FPS

FPS for rendering entities is improved, on of the yet few improvements for client side only.

Login/playing timeout

Configurable login timeouts for logging in and disconnecting while playing, helping players with slower PC's and connections.

Recipe caching

Recipe lookups get a lot faster, helping with all those autocrafting mods out there causing lag when looking through the vast amount of recipes.

Fast world updates

Random block and chunk ticks are faster overall and cost less performance.

Configurable utilities

Disable entity spawns for specific types of entities.
Debug setting for show non-normal chunk loads.
Debug settings for showing 

Fixes:

Leashing lag, lag caused by leashed entities.
Advancement lag caused by checking inventories
Entities loading chunks when they should not

and many more smaller ones you can find in the configs.

commands for profiling/locating lag sources:

note that these only gather data when your TPS is low and performant starts doing load balancing

starts recording lag data:

/performant startGatherData

Reports lagging entities and stops recording:

/performant reportEntities

Reports lagging tileentities and stops recording:

/performant reportTileEntities

Reports any currently slowed down event subscribers
/performant reportEvents