AI Improvements: Performance Tuning in All the Mons

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]

Same as in the All the Mods 10 2.11 guide

This mod has no machines, multiblocks, power, fluids or items. It works entirely behind the scenes: it changes how vanilla mob AI runs so your CPU does less work, and it lets you switch off some AI behaviors completely.^[1]

It targets common problems in big modded worlds, such as too many animals and the performance hit from swarms of zombies. It also handles simple removal tasks that larger AI overhaul mods skip.^[1]

How it saves performance

The details depend on the feature and the Minecraft version. Most of the gain comes from caching values that are expensive to calculate. That cuts CPU time and costs only a negligible amount of extra RAM.^[1]

The mod is written to work on the server alone, so your players don't need it installed. You can also run it on the client only, but it may not do much for your FPS.^[1]

The three features

The main feature replaces Minecraft's look helper, the code mobs use to work out where to point their heads, with a more efficient version. The custom version stores some data so it can calculate the angle to a location faster. The project page lists this as enabled by default.^[1]

The mod author tested this with VisualVM and measured a 50% to 80% drop in CPU usage by the AI code. On a server with 25 people online constantly, TPS went from 5 to 7.^[1]

The second feature is an option to remove the Watch Closest Entity AI task, which makes mobs turn their heads toward a nearby entity. It is off by default. Turning it on frees up a lot of CPU, but the author warns it causes a few odd visual issues.^[1]

The third feature is an option to disable the look random (look idle) AI. Almost every mob runs this when it has nothing important to do, so switching it off can help servers with large mob populations. It is also off by default. The visual side effect is that mob heads sometimes don't rotate, which mostly goes unnoticed.^[1]

Setting your expectations

Don't expect big gains in every situation. Newer Minecraft versions already include their own AI fixes, including a rotation fix, so the mod has much less impact than it did on older versions. The author recommends testing your own results to decide whether you need it.^[1]

Unverified The project page names the config file as config/bbm/AI_Improvements.cfg and uses AI class names from older Minecraft versions. No config file for this mod was found in the pack, so the file location, option names and the values this pack uses on this Minecraft version could not be confirmed. The benchmark figures above come from the author's own testing, not from this pack.

Same as in the All the Mods 10 2.11 guide

The mod is built around performance improvements for vanilla AI, plus the ability to turn off certain AI behaviors. In this pack there is no config file for it, so there are no pack-side overrides to worry about and no toggles for you to flip from the config folder.^[1]

Unverified The mod may still have configurable options that are generated or edited elsewhere, but no config file or option names for it could be confirmed in this pack.

All the Mons 1.3.0 includes AI Improvements: Performance Tuning 0.5.3, using the file AI-Improvements-1.21-0.5.3.jar. It was first included in All the Mons 0.3.0-beta or earlier.^[3]

Mod changelog

• 0.5.3: updated to Minecraft 1.21. This is the only change listed in the mod's changelog for that version.^[4]