berryber09/MiniMax-H3-Fun-Controlnet-Union-w4a8

MiniMax-H3 Fun ControlNet-Union, pruned, W4A8

W4A8 quantization of the MiniMax-H3 Fun ControlNet-Union model patch for ComfyUI.

File	minimax_h3_fun_controlnet_union_pruned_w4a8.safetensors
Size	1.45 GB (bf16 pruned build: 4.22 GB, int8_convrot build: 2.3 GB)
Source	alibaba-pai/MiniMax-H3-Fun-Controlnet-Union, via the pruned bf16 build in Comfy-Org/MiniMax-H3
sha256	fe822947667d7625e0c622edc583952628f9ccf749a7444af11b2eb9747f3bdc

Quantization

• Format: asym_w4a8_int8 (4-bit asymmetric weights, int8 activations), ConvRot rotation with group size 256, weight group size 16.
• Applied to the 20 2D projection layers of the 5 control blocks. Norms, embeddings, biases and the AdaLN basis stay in bf16/fp32.
• Calibration-free (reference format). Quantization metadata is stored in the safetensors header (_quantization_metadata, comfy_wxa8), the layout ComfyUI reads natively.

Usage (ComfyUI)

1. Put the file in models/model_patches/.
2. Load it with ModelPatchLoader, apply with MiniMaxH3FunControlNetApply (see the bundled template video_minimax_h3_fun_controlnet_union).
3. Requires ComfyUI 0.35.0 or newer. This file carries native quantization metadata; the Comfy-Org int8_convrot build uses the legacy scale-tensor format and needs Comfy-Org/ComfyUI#16221 on 0.35.0.

Notes

• Loads and builds all 5 control blocks. Output quality relative to the bf16 and int8_convrot builds has not been measured.
• License follows the source model (MiniMax-H3 Community License Agreement).