---
language:
  - en
license: other
license_name: ltx-2-community
license_link: https://huggingface.co/Lightricks/LTX-2.3/blob/main/LICENSE
library_name: mlx
tags:
  - mlx
  - video-generation
  - diffusion
  - apple-silicon
  - ltx-video
  - text-to-video
  - audio-video
  - quantized
  - 4-bit
base_model: Lightricks/LTX-2.3
pipeline_tag: text-to-video
---

# LTX-2.3 22B Distilled (MLX, 4-bit quantized)

MLX-optimized 4-bit quantized weights for [Lightricks/LTX-2.3](https://huggingface.co/Lightricks/LTX-2.3) video generation model. Fits on **32GB Apple Silicon Macs**.

Also available in [full float16 precision](https://huggingface.co/gajesh/LTX-2.3-mlx-fp16) (66GB, for 64GB+ Macs).

## Model Details

- **Model**: LTX-2.3 22B Distilled (joint audio-video diffusion transformer)
- **Format**: MLX safetensors (4-bit quantized transformer, float16 VAE/text encoder)
- **Transformer Size**: 11GB (down from 39GB, 3.6x compression)
- **Total Size**: ~35GB
- **Minimum RAM**: 32GB Apple Silicon Mac
- **Original**: [Lightricks/LTX-2.3](https://huggingface.co/Lightricks/LTX-2.3)

## Quantization Details

- **Method**: Post-training quantization via `mlx.nn.quantize()`
- **Bits**: 4-bit
- **Group Size**: 64
- **Quantized Layers**: All Linear layers in the transformer (22B params)
- **Full Precision**: VAE decoder, upsampler, text encoder, normalization layers, embeddings

## Benchmarks (M4 Max 128GB)

Head-to-head comparison on the same machine, same config (576x1024, 121 frames, 5s video):

| | PyTorch MPS (BF16) | MLX Q4 (Video-only) | MLX FP16 (Video-only) |
|---|---|---|---|
| **Stage 1** (8 steps, half-res) | 66.7s | **51.1s** | 51.2s |
| **Stage 2** (3 steps, full-res) | 157.9s | **101.3s** | 101.3s |
| **Total denoising** | **264.0s** | **154.3s** | **152.5s** |
| **Speedup** | 1.0x | **1.7x** | **1.7x** |
| **Peak memory** | >60 GB | **29.9 GB** | 34.2 GB |
| **Model size** | 46 GB | **11 GB** | 39 GB |

4-bit quantization achieves virtually identical speed to FP16 while reducing:
- **Model size**: 39GB -> 11GB (3.6x smaller)
- **Peak memory**: 34.2GB -> 29.9GB (fits on 32GB Macs)

## Usage

```python
from mlx_ltx.pipeline import DistilledPipeline, save_video

pipeline = DistilledPipeline("path/to/mlx-weights-q4")
video = pipeline(
    prompt="A cat surfing on ocean waves at sunset",
    height=576, width=1024, num_frames=121,
    seed=42,
)
save_video(video, "output.mp4", fps=24.0)
```

## License

[LTX-2 Community License](https://huggingface.co/Lightricks/LTX-2.3/blob/main/LICENSE)