Z-Image-FP8 / README.md
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---
base_model: Tongyi-MAI/Z-Image
base_model_relation: quantized
license: apache-2.0
pipeline_tag: text-to-image
tags:
- text-to-image
- diffusion
- fp8
- quantized
- comfyui
---
# Z-Image ยท FP8 (transformer)
FP8 (`float8_e4m3fn`) quantization of the **Z-Image DiT (ZImageTransformer2DModel, 6.1B)** transformer from [`Tongyi-MAI/Z-Image`](https://huggingface.co/Tongyi-MAI/Z-Image). Quantized by **axteam**.
| File | Size |
|---|---|
| `Z-Image-transformer-fp8_e4m3fn.safetensors` | 6.2 GB |
## What this is
- **Only the transformer (DiT) is quantized** to `float8_e4m3fn` (2-D weight tensors; norms/biases kept in BF16). ~half the size of the BF16 transformer.
- **VAE and text encoder(s) are NOT included** โ€” use the ones from the original [`Tongyi-MAI/Z-Image`](https://huggingface.co/Tongyi-MAI/Z-Image).
## Requirements
| | |
|---|---|
| **Runtime** | ComfyUI (Load Diffusion Model node, `float8_e4m3fn` single file). Not run here โ€” no ComfyUI on this server. |
| **Also needed** | the Qwen3 text encoder (8.0 GB) and VAE (0.17 GB) from the base repo. |
| **Memory** | this file is **6.2 GB**; add the text encoder(s) and VAE above. |
## Usage (ComfyUI)
1. Download the FP8 file into ComfyUI's diffusion-model folder:
```bash
hf download axteam/Z-Image-FP8 Z-Image-transformer-fp8_e4m3fn.safetensors --local-dir ComfyUI/models/diffusion_models
```
2. Get the **VAE** and **text encoder(s)** from the original [`Tongyi-MAI/Z-Image`](https://huggingface.co/Tongyi-MAI/Z-Image) repo (or the matching ComfyUI repackaged files) and put them in `ComfyUI/models/vae/` and `ComfyUI/models/text_encoders/`.
3. In your workflow, load this file with the **Load Diffusion Model** node (`UNETLoader`) โ€” leave `weight_dtype` at `default` (the file is already `float8_e4m3fn`) โ€” and wire the original VAE / text-encoder loaders as in the base model's reference workflow.
4. Sampler settings (steps, CFG/guidance, resolution) are the same as for the original model.
> The FP8 file is a plain cast of the transformer weights (no scaling), the common ComfyUI `fp8_e4m3fn` convention; norms and biases stay BF16.
## License
Quantized derivative of [`Tongyi-MAI/Z-Image`](https://huggingface.co/Tongyi-MAI/Z-Image). Original weights belong to the upstream authors; the base model's license applies to this derivative.
---
## ํ•œ๊ตญ์–ด ์š”์•ฝ
[`Tongyi-MAI/Z-Image`](https://huggingface.co/Tongyi-MAI/Z-Image) ์˜ **transformer(DiT)๋งŒ FP8(`float8_e4m3fn`)** ๋กœ ์–‘์žํ™”(2D ๊ฐ€์ค‘์น˜๋งŒ, norm/bias๋Š” BF16). BF16 ๋Œ€๋น„ ์•ฝ ์ ˆ๋ฐ˜ ํฌ๊ธฐ. VAEยทํ…์ŠคํŠธ์ธ์ฝ”๋”๋Š” ๋ฏธํฌํ•จ(์›๋ณธ ์‚ฌ์šฉ). ComfyUI `models/unet/` ์— ๋„ฃ์–ด ์‚ฌ์šฉ. ์ž‘์„ฑ axteam.
- **์š”๊ตฌ์‚ฌํ•ญ** โ€” ComfyUI(Load Diffusion Model). ํŒŒ์ผ 6.2 GB + ๊ธฐ๋ฐ˜ ๋ฆฌํฌ์˜ ํ…์ŠคํŠธ ์ธ์ฝ”๋”ยทVAE. ์ด ์„œ๋ฒ„์—์„œ๋Š” ๋ฏธ์‹คํ–‰.
- **์‹คํ–‰(ComfyUI)** โ€” `hf download axteam/Z-Image-FP8 <ํŒŒ์ผ> --local-dir ComfyUI/models/diffusion_models` ๋กœ ๋ฐ›๊ณ , VAEยทํ…์ŠคํŠธ ์ธ์ฝ”๋”๋Š” ์›๋ณธ์—์„œ ๋ฐ›์•„ `models/vae`, `models/text_encoders` ์— ๋‘” ๋’ค **Load Diffusion Model** ๋…ธ๋“œ๋กœ ๋ถˆ๋Ÿฌ์˜ต๋‹ˆ๋‹ค(`weight_dtype` ์€ default). ์ƒ˜ํ”Œ๋Ÿฌ ์„ค์ •์€ ์›๋ณธ๊ณผ ๊ฐ™์Šต๋‹ˆ๋‹ค.