ImmediatelyFast guide for All the Mods 10 2.12

Same as in the All the Mods 10 8.1 guide

ImmediatelyFast is an open source, client-side performance mod. It speeds up immediate mode rendering, and it's built to be lightweight and play nicely with other mods. It adds no gameplay of its own. You install it and get smoother FPS.^[1]

In this pack you get the NeoForge build 1.6.13+1.21.1. It has been in the pack since All the Mods 10 2.25 or earlier.^[2]

What it speeds up

It swaps in a custom buffer implementation that batches draw calls and uploads data to the GPU more efficiently. That generally covers these areas:^[1]

• Entities and block entities^[1]
• Particles^[1]
• Text rendering^[1]
• GUI and HUD^[1]
• Immediate mode rendering from other mods^[1]

It also replaces some vanilla code with faster versions for map rendering, HUD rendering and text rendering.^[1]

Who it helps

Anyone whose CPU is the bottleneck. The mod's author says it can only raise FPS in that situation, and that slower CPUs benefit more than very fast ones. You'll notice it most around lots of entities, many maps, or many signs.^[1]

The author's own test with 1000 cows on screen went from 16 FPS to 60 FPS. Those numbers came from a Ryzen 5 1600 with a GTX 1060, on Minecraft 1.19.3 with an older version of the mod. Treat them as an example of the effect, not a promise for this pack.^[1]

Config and compatibility

The mod has a config file in your instance's config folder. The author recommends leaving most options at their defaults. If HUD elements act strangely, the author suggests turning off the hud_batching option. The values this pack ships for these options aren't shown in the sources.^[1]

The author lists OptiFabric and OptiFine as known incompatibilities, along with most closed source clients such as LunarClient and LabyMod.^[1]

Unverified The sources don't show where this mod fits in the pack's progression. They don't show it on the ATM Star path, and they don't show any quests, items or recipes tied to it.

Same as in the All the Mods 10 8.1 guide

Good news: there's nothing to craft or set up first. ImmediatelyFast is a rendering optimization mod. It improves the immediate mode rendering performance of the client and is designed to be lightweight and compatible with other mods.^[1]

Unverified I couldn't confirm any items, recipes or quests for this mod in this pack, so there is no crafting order to follow and no recipe blocks to show.

What it speeds up

The mod uses a custom buffer implementation that batches draw calls and uploads data to the GPU more efficiently. That applies to these areas:^[1]

• Entities and block entities^[1]
• Particles^[1]
• Text rendering^[1]
• The GUI and HUD^[1]
• Immediate mode rendering from other mods^[1]

It also replaces some vanilla code with faster versions, specifically for map rendering, HUD rendering and text rendering.^[1]

What to expect

The mod only helps when your CPU is the bottleneck. That is most likely the case unless your GPU is ancient or you run very heavy shaders. Slower CPUs benefit more than really fast ones.^[1]

The mod's author reports the biggest gains in busy scenes: roughly 2x higher FPS with many entities or many signs around you, and roughly 5x higher with many maps on screen. Those figures were measured with older mod versions on Minecraft 1.19.3, not in this pack, so treat them as a rough guide to where the mod helps rather than what you'll see here.^[1]

Heads up first: ImmediatelyFast has no machines, multiblocks, power, fluids or item logistics. It's a rendering optimization mod that improves the immediate mode rendering performance of the client, and it's designed to be lightweight and compatible with other mods. Its core mechanics are all about how your game draws things on screen, and they're controlled through one config file.^[1]

How the batching works

The main trick is a custom buffer implementation. It batches draw calls and uploads data to the GPU more efficiently. Instead of the game sending lots of small drawing jobs one at a time, the mod groups them together. It applies this to these parts of immediate mode rendering:^[1]

• Entities^[1]
• Block entities^[1]
• Particles^[1]
• Text rendering^[1]
• GUI and HUD^[1]
• Immediate mode rendering done by other mods^[1]

On top of the general batching, the mod has targeted optimizations that replace some vanilla rendering code with a faster implementation. These cover map rendering, HUD rendering and text rendering.^[1]

When it actually helps

This is important for setting your expectations. The mod can only raise your FPS when your CPU is the bottleneck, which is most likely the case unless your GPU is very old or you're running very heavy shaders. Slower CPUs benefit more than really fast ones.^[1]

The mod's own benchmarks give a sense of scale, but they're old. They were tested on Minecraft 1.19.3 with earlier versions of the mod. They suggest about 2x higher FPS on busy servers with lots of entities, about 5x higher with many maps on screen, about 40% higher for HUD rendering, about 2x higher with lots of signs or holograms, and about 20% higher with many block entities around you. Treat these numbers as rough indicators, not guarantees for your setup.^[1]

The optimizations switched on in this pack

The config file splits its options into regular, cosmetic, experimental and debug groups. In this pack, all of the regular optimizations are enabled:^[3]

• font_atlas_resizing is set to true. It increases the size of the font atlas textures, which improves performance with high resolution or custom server fonts.^[1][3]
• map_atlas_generation is set to true. It puts map textures into a single texture instead of many separate ones, which helps when lots of maps are on screen.^[1][3]
• hud_batching is set to true. It speeds up HUD rendering by submitting fewer draw calls.^[1][3]
• fast_text_lookup is set to true. It caches some data between rendering text characters, which slightly helps when a lot of text is being drawn.^[1][3]
• fast_buffer_upload is also set to true.^[3]

Experimental and debug options

The config labels its experimental section with a warning that rendering glitches may occur. In this pack, every experimental option is off: experimental_screen_batching, experimental_sign_text_buffering, experimental_universal_hud_batching, experimental_disable_error_checking and experimental_disable_resource_pack_conflict_handling are all set to false.^[3]

There's also a cosmetic section, which the config says does not optimize anything. Its option dont_add_info_into_debug_hud is set to false in this pack.^[3]

Compatibility

The mod is built to interfere with other mods as little as possible and should work with most mods and modpacks. Its known incompatibilities are OptiFine and OptiFabric, plus most closed source clients such as LunarClient and LabyMod.^[1]

Unverified The exact behavior of fast_buffer_upload and of each experimental option isn't described in the available sources. The same goes for what the debug HUD shows when dont_add_info_into_debug_hud is false. It's also unconfirmed whether any of this pack's values differ from the mod's defaults.

ImmediatelyFast is a client-side rendering optimization mod, so its config is all about how aggressively it batches and uploads draw calls. The pack ships a single config file with every option left at a safe, stable setting, so you can play without touching anything.^[1][3]

The options that are on

The regular optimizations are all enabled in this pack. These are the ones doing the actual work, and they're the reason the mod helps at all, so leave them on unless you're chasing down a rendering bug.^[3]

• fast_buffer_upload is true, which covers the more efficient way the mod gets vertex data to the GPU.^[1][3]
• fast_text_lookup is true, part of the mod's text rendering optimizations.^[1][3]
• font_atlas_resizing is true.^[3]
• hud_batching is true, batching the HUD draw calls the mod targets with a faster implementation.^[1][3]
• map_atlas_generation is true, tied to the mod's map rendering optimization.^[1][3]

Experimental options (all off here)

The config file labels this group as experimental and warns that rendering glitches may occur. The pack leaves every one of them disabled, so if you flip one on you're stepping outside the tested setup.^[3]

• experimental_screen_batching is false.^[3]
• experimental_sign_text_buffering is false.^[3]
• experimental_universal_hud_batching is false.^[3]
• experimental_disable_error_checking is false.^[3]
• experimental_disable_resource_pack_conflict_handling is false, so resource pack conflicts are still handled.^[3]

Debug options: don't touch

The config marks the last group as debug only and tells you not to touch it. Everything in it is false in this pack, including debug_only_and_not_recommended_disable_hardware_conflict_handling, debug_only_and_not_recommended_disable_mod_conflict_handling, debug_only_and_not_recommended_disable_universal_batching, debug_only_print_additional_error_information and debug_only_use_last_usage_for_batch_ordering.^[3]

The one cosmetic toggle

dont_add_info_into_debug_hud is the only cosmetic setting, and the config file is clear that cosmetic values don't optimize anything. It's false in this pack, so ImmediatelyFast adds its info to the F3 debug screen. Set it to true if you'd rather keep that screen tidy; it won't change your FPS.^[3]

Unverified Whether these values differ from ImmediatelyFast's own defaults isn't confirmed by the sources here; treat the list above as what the pack ships, not as a list of pack overrides.

All the Mods 10 2.12 ships ImmediatelyFast 1.3.3+1.21.1, the NeoForge build (file ImmediatelyFast-NeoForge-1.3.3+1.21.1.jar). The mod was already in the pack by version 1.7 or earlier. Here is what the mod's own changelogs say for versions 1.3.0 to 1.3.3, newest first.^[4][5][6]

Changes by release

• 1.3.3: Added support for Minecraft 1.21.4 on Fabric and NeoForge. The Forge build was marked as clientside only, which is a visual change only.^[4]
• 1.3.2: Text layer draw order is now enforced, which fixes layering issues with custom fonts in server resource packs. Two further changes are marked 1.21.2+ only: Forge support was readded, and compatibility with NeoForge 21.3.23+ was fixed.^[7]
• 1.3.1: Fast buffer upload went back to the old approach. The previous method used a streaming buffer, which didn't show much extra performance, was a lot more complex and error-prone, and doesn't work on older GPUs. If you see a big performance drop or graphical glitches after updating, the changelog asks you to open an issue on the mod's GitHub repository.^[8]
• 1.3.1, 1.21.2+ only: Fixed a performance regression on Apple GPUs, limited screen batching to container items and the chat screen, and added a workaround for an item cooldown render order issue.^[8]
• 1.3.0: Added support for Minecraft 1.21.2/1.21.3, dropped support for 1.20.5/1.20.6, and fixed wolf collar rendering order.^[5]
• 1.3.0, 1.21.2+ only: Fast buffer upload was rewritten to have less overhead in high (1000+) FPS scenarios, and experimental universal HUD batching was made more efficient. The ImmediatelyFast batching API was deprecated, because Mojang added basic batching into the DrawContext class and the mod now uses and extends that system.^[5]