---
license: apache-2.0
base_model: Qwen/Qwen-Image-Edit-2511
tags:
- comfyui
- quantization
- int4
- w4a4
- convrot
- qwen-image-edit
---

# Qwen-Image-Edit-2511 — INT4 tensorwise W4A4 (+ConvRot, mixed int8 fallback)

**W4A4** quantization of [Qwen-Image-Edit-2511](https://huggingface.co/Qwen/Qwen-Image-Edit-2511):
weights in packed signed INT4 (2/byte) with group-256 regular-Hadamard **ConvRot**
rotation (arXiv [2512.03673](https://arxiv.org/abs/2512.03673)), activations rotated
online and dynamically quantized to INT4 inside the kernel. Calibration-free.

**Mixed-precision quality recipe** (validated end-to-end): 480 layers INT4 + 359
sensitive layers (attention value/output projections **and the adaLN modulation
Linears — critical**) stored as stock `int8_tensorwise` in the same checkpoint.
The `__index_timestep_zero__` sentinel is included (2511 reference-image mode).

## Samples

![BF16 vs INT4 comparison](samples_qwen.jpg)

Same seed/prompt edit samples, BF16 top vs INT4-mixed bottom.

## ⚠️ Runtime requirement

Needs the `int4_tensorwise` runtime, which is **not in any released ComfyUI /
comfy-kitchen yet**. In-flight:
[comfy-kitchen PR #63](https://github.com/Comfy-Org/comfy-kitchen/pull/63)
(kernels + layout) and the
[ComfyUI loader branch](https://github.com/HK416-TYPED/ComfyUI/tree/feat/int4-tensorwise-loader)
— to try this checkpoint today, run that ComfyUI branch with the PR's
comfy-kitchen branch on `PYTHONPATH` (or installed). On a stock release it
fails with a clear "format not available" error.

## Measurements

Quality (L4, 20-step edit sample, mean over 4 prompts, PSNR vs bf16-sentinel):

| checkpoint | size | PSNR |
| --- | --- | --- |
| int8_tensorwise | 20.0 GB | 30.05 dB |
| **this model (int4 mixed)** | **14.9 GB** | 26.58 dB |
| bf16 | 40 GB | — |

Speed (NVIDIA L4 / SM 8.9 — native INT4 tensor cores; 20-step image, steady state,
same-session comparison, fused ConvRot + rank-one s4 MMA kernel):

| path | s/image |
| --- | --- |
| **this model (int4 mixed)** | **87.1** |
| int8_tensorwise (CUDA kernels) | 93.1 |
| bf16 | 114 |

## Reproduce

```bash
comfy-quants export-model-int4-tensorwise \
  --config configs/qwen_image_edit_2511_int4_tensorwise_mixed.yaml \
  --source /path/to/Qwen-Image-Edit-2511/transformer \
  --out qwen_edit_2511_int4tw_mixed.safetensors
```

Produced by [comfy-quants](https://github.com/Comfy-Org/comfy-quants) (branch
`feat/int4-tensorwise`). A higher-quality variant (+MLP down-projections at int8,
17.2 GB / 27.19 dB) is one config edit away — see the config comments.