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license: other
license_name: ltx-2-community-license-agreement
license_link: https://github.com/Lightricks/LTX-2/blob/main/LICENSE
base_model: Lightricks/LTX-2.3
tags:
- ltx-2
- video
- comfyui
- int8
- quantized
---
# LTX-2.3 22B dev — INT8 tensorwise (+ConvRot), stock-ComfyUI native
Offline INT8 quantization of `Lightricks/LTX-2.3` (`ltx-2.3-22b-dev.safetensors`),
produced with [Comfy-Org/comfy-quants](https://github.com/Comfy-Org/comfy-quants)
(`export-model-int8-tensorwise`). Loads **natively in stock ComfyUI >= v0.27.0**
(`QUANT_ALGOS["int8_tensorwise"]`, SM >= 7.5 / Turing+) — no custom node required.
## Contents
Single-file bundle (drop into `models/checkpoints/`, load via `CheckpointLoaderSimple`;
`LTXAVTextEncoderLoader` and `LTXVAudioVAELoader` read the text-embedding projection /
audio VAE / vocoder from the same file). Text encoder (Gemma-3-12B) not included —
use e.g. `Comfy-Org/ltx-2` `gemma_3_12B_it_fp4_mixed.safetensors`.
## Quantization contract
- 1,496 quantized Linears (blocks 2–45 incl. `to_gate_logits`; blocks 0/1/46/47 kept
bf16) — **layer-for-layer identical to the official `Lightricks/LTX-2.3-fp8` /
`-nvfp4` releases**.
- Per layer: `int8` weight + `float32 [out,1]` scale + `comfy_quant` marker
`{"format": "int8_tensorwise", "convrot": true, "convrot_groupsize": 256}`
(byte-exact to stock ComfyUI's own save path). All 1,496 layers ConvRot-rotated.
- Quant math bit-faithful to comfy-kitchen >= 0.2.15 (`quantize_int8_convrot_weight`).
- VAE / audio VAE / vocoder / text-embedding projection copied verbatim (bf16/f32).
## Measured (RTX PRO 6000 Blackwell, 512²×49f+audio, 20 steps, torch 2.10.0+cu130)
| | bf16 | this artifact |
|---|---|---|
| Disk | 46.1 GB | **29.2 GB** |
| Peak VRAM (full pipeline) | 53.7 GB | **38.6 GB (−28%)** |
| Sampling speed | 2.37 it/s | **2.73 it/s (1.15×)** |
| Video PSNR vs bf16 | — | **45.4 dB** |
Best fidelity and the only faster-than-bf16 format among fp8/mxfp8/nvfp4/int8 on this
model.
## License
Inherits the **LTX-2 Community License Agreement** from the base model (free below
$10M annual revenue; derivatives must remain under the same license). See the license
link above and the `license` field embedded in the checkpoint metadata.
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