AI Improvements: Performance Tuning guide for All the Mods 10 0.32 to 0.50

Same as in the All the Mods 10 8.1 guide

AI Improvements: Performance Tuning is a small, server-minded mod that makes vanilla mob AI cheaper to run. It also lets you switch off certain AI behaviors. It targets problems like too many animals and performance hits from swarms of zombies.^[1]

This pack ships version 0.5.3 of the mod. It has been in the pack since 2.25 or earlier.^[2]

How it helps

Most of the gain comes from caching heavily calculated values. That cuts CPU time at the cost of an ignorable amount of RAM. The main feature replaces the game's EntityLookHelper with a more efficient version that stores data to find the angle to a location faster. The author's VisualVM testing showed a 50% to 80% decrease in CPU usage by the AI code. On a server with 25 people online constantly, that meant a gain from 5 to 7 tps.^[1]

The mod also has two optional switches. One removes the AI segment that makes mobs turn their heads toward a nearby entity. The other removes the 'look idle' AI. The author says both can free up CPU, with the visual cost of odd or missing head rotation. The project page describes both as off by default.^[1]

Who it is for

It is built for large, heavily modded servers where mobs and other entities eat into CPU time. You can install it on the server only, since it works without a client-side copy. Client-only installs are possible, but it may not do much for your fps.^[1]

Unverified The sources do not show how the pack configures this mod, so the defaults described above come from the mod's project page and are not confirmed as this pack's values. They also do not show any quest or ATM Star path involvement, so there is no progression step tied to it.

Same as in the All the Mods 10 8.1 guide

This one is different from most mods in the pack: AI Improvements: Performance Tuning isn't something you craft or build with. It works quietly in the background, making vanilla mob AI cheaper to run and letting you switch off certain AI behaviors. So your first steps are about testing and settings, not items.^[1]

Unverified The sources here show no recipes, quests or guidebook entries for this mod, so there is no first item to craft. The option defaults below are the mod's own defaults from its project page, and the sources here do not show whether the pack changes any of them.

What to do first

1. Measure before you decide. The mod's author says it isn't expected to improve performance in every case, so test your results to see whether you actually need it.^[1]
2. Know where it runs. It can be installed on the server only, which is the setup it grew out of. It also works on the client only, though it may not do much for your FPS there.^[1]
3. Set your expectations. Newer Minecraft versions already include AI fixes, such as the rotation fix, so the gain is much smaller than in older versions.^[1]
4. Find the config. The project page says the mod's config file is at .minecraft/config/bbm/AI_Improvements.cfg.^[1]

The main options

The project page describes these config options, with the defaults the mod ships with. Most of the savings come from caching heavily calculated values, which trades a negligible amount of RAM for less CPU time.^[1]

• Disable AI Watch Closest Entity: off by default. When on, it removes the AI segment that makes mobs turn their heads toward nearby entities. It frees up a lot of CPU, but you may notice some odd visuals.^[1]
• Disable AI look random: off by default. When on, entities stop using the idle look AI. This can help servers with large populations, and the only visible effect is that heads sometimes don't rotate, which mostly goes unnoticed.^[1]
• Replace EntityLookHelper with a more efficient version: on by default. If you turn it off, you won't see much AI improvement, though the other disable options should still work fine.^[1]

This one has no machines, multiblocks or power of any kind. It's a pure performance mod that reaches into how Minecraft runs entity AI and trims the expensive parts, so everything here happens invisibly in the background while your world ticks.^[1]

The mod describes itself as a simplified AI modification focused on performance and low-level changes to the game's AI, picking up slack from the base game for a modded ecosystem. The problems it targets are the ones that hurt big servers: too many animals, the performance hit from swarms of zombies, and small removable tasks that larger AI overhaul mods skip.^[1]

How the speedup actually works

Most of the gain comes from caching heavily calculated values. Instead of recomputing the same AI math every tick for every entity, the mod stores results and reuses them, trading a small and ignorable amount of RAM for reduced CPU time. The exact benefit depends on the feature and the Minecraft version you're on.^[1]

The rest comes from simply not running AI segments you don't need. Two of the three features are opt-in switches that strip a behavior out of entities entirely, which frees the CPU time those behaviors would have spent.^[1]

The three features

The headline feature is a replacement for Minecraft's look helper, and it is enabled by default. The custom version stores some data that makes it faster to work out the angle toward a location. Testing with VisualVM showed a 50% to 80% decrease in CPU usage by the AI code, and on a server with 25 people online constantly that translated to a gain of 5 to 7 TPS.^[1]

The second feature disables the AI segment that makes mobs watch the closest entity, the code that rotates a mob's head toward something nearby. It is off by default, so nothing changes until you turn it on. Switching it on causes a few odd visual issues, but it frees up a lot of CPU usage caused by entities.^[1]

The third feature disables the 'look idle' AI, the random head-turning mobs do when they have nothing better to do. It is also off by default. Because almost every entity on the map uses this behavior while idle, turning it off can improve performance on servers with large populations, and visually it mostly goes unnoticed beyond heads occasionally not rotating.^[1]

Client, server and configuration

The mod is coded to work without being installed client-side, so it's safe to add to a server only. It can also run client-only, though it may not do much for your FPS, since the work it saves is AI tick time rather than rendering.^[1]

The mod documents its settings as living in a file named AI_Improvements.cfg inside a bbm folder in the config directory. All three features above are toggles in that file.^[1]

Unverified The config file is not shipped with the pack, so it is generated with the mod's own defaults on first launch and the exact key names in this version are not confirmed here.

What to expect

Be realistic about the payoff. The mod's own notes say it is not expected to improve performance in all cases, and you should test your results to see whether you actually need it. Newer Minecraft versions implement their own AI fixes, including a rotation fix, so the impact of this mod is much lower than it was in older versions.^[1]

The mod's project page describes it as performance improvements for vanilla AI, with the ability to turn off certain AI behaviors. That is the main thing to know about its options.^[1]

Unverified This guide has no config file for this mod in the pack, so the names of its individual config options, their default values and any values the pack changed from those defaults are unverified.

All the Mods 10 0.50 ships AI Improvements: Performance Tuning version 0.5.3, using the file AI-Improvements-1.21-0.5.3.jar. The mod has been in the pack since 0.32 or earlier, so it's been part of All the Mods 10 for a good while.^[3]

The only mod changelog entry I have is for 0.5.3, which updated the mod to Minecraft 1.21.^[4]

Unverified The pack changelogs have no entries for this mod, so any changes to it between pack releases are unverified here.