Z-Image Turbo — NVFP4 pack for ComfyUI
An NVFP4-quantized build of Z-Image Turbo plus everything ComfyUI needs to run it, packaged for Blackwell GPUs (RTX 5090, DGX Spark / GB10) where NVFP4 runs natively.
The full writeup — how it was quantized and how it actually performs — is at ai-muninn.com.
What's in the pack
| File | Role | Size |
|---|---|---|
z_image_turbo_nvfp4.safetensors | Z-Image Turbo diffusion model — NVFP4 | 4.5 GB |
ae.safetensors | VAE (autoencoder) | 335 MB |
qwen_3_4b.safetensors | Qwen3-4B text encoder (bf16) | 8.0 GB |
qwen_3_4b_fp8_mixed.safetensors | Qwen3-4B text encoder (FP8 mixed) | 5.6 GB |
gemma_3_12B_it_fp4_mixed.safetensors | Gemma-3-12B-IT text encoder (FP4 mixed) | 9.4 GB |
Z-Image-Turbo-Fun-Controlnet-Union.safetensors | ControlNet Union | 3.1 GB |
Why NVFP4
NVFP4 is Blackwell's native 4-bit format. On a 5090 / GB10 it roughly halves the diffusion model's VRAM versus fp8/bf16 while keeping the tensor cores fed — so Z-Image Turbo's few-step generation stays fast without spilling to system RAM. FP8 / FP4 text-encoder variants are included so you can trade quality vs. footprint on the encoder side too.
Use in ComfyUI
Drop the files into your ComfyUI model folders:
z_image_turbo_nvfp4.safetensors→models/diffusion_models/ae.safetensors→models/vae/qwen_3_4b*.safetensors/gemma_3_12B_it_fp4_mixed.safetensors→models/text_encoders/Z-Image-Turbo-Fun-Controlnet-Union.safetensors→models/controlnet/
Credits & licensing
- Base model —
Tongyi-MAI/Z-Image-Turbo· Apache-2.0 - ControlNet —
alibaba-pai/Z-Image-Turbo-Fun-Controlnet-Union· Apache-2.0 - Text encoders — Qwen3-4B (Apache-2.0). The bundled
gemma_3_12B_it_fp4_mixedfile is Google Gemma-3, covered by the Gemma Terms of Use, not Apache-2.0 — use that file under those terms.
NVFP4 quantization & packaging by ai-muninn. This repackaging is Apache-2.0; the Gemma component keeps its own license as noted above.