endman100/MiniMax-H3-FL2VA-FP8

MiniMax H3 FL2VA FP8 E4M3FN for ComfyUI

Unofficial mixed-precision FP8 conversion of the MiniMax H3 FL2VA diffusion model for ComfyUI. FL2VA is the MiniMax H3 task checkpoint for text-to-audio-video and native first-frame, last-frame, or first-and-last-frame conditioning.

File

• minimax_h3_fl2va_fp8_e4m3fn.safetensors
• Size: 33,236,581,696 bytes (30.954 GiB)
• SHA-256: E5C2E4390756BB673E44310BECF7317EB262C1BD969936FB50AC64E7774A73AF

Conversion

The official BF16 checkpoint was converted tensor-by-tensor without materializing the complete checkpoint in RAM or VRAM. Multi-dimensional BF16 weight tensors were converted to FP8 E4M3FN. Normalization, bias, conditioning, final-layer, and time-embedding tensors retained BF16 or FP32 precision.

• Total tensors: 535
• FP8 E4M3FN tensors: 258
• BF16 tensors: 264
• FP32 tensors: 13
• Source file: minimax_h3_fl2va_bf16.safetensors
• Source size: 66,280,487,368 bytes
• Source SHA-256: 907D4ADD438438EC1544F5240C3B38532ED934FE6BE75677A6BBDA2A6FDD6182

Tensor names and shapes were checked against the source checkpoint and match exactly. The output safetensors data ranges cover the complete file without gaps or truncation.

ComfyUI

Place the checkpoint in ComfyUI/models/diffusion_models/ and load it with the standard UNETLoader using weight_dtype: default.

For native first/last-frame control, use the core MiniMaxH3ImageToVideo node and connect images to its first_frame and/or last_frame inputs. This FL2VA checkpoint is different from the Ref2VA checkpoint used by MiniMaxH3ReferenceToVideo; it does not add Ref2VA multi-reference conditioning.

Verified locally with ComfyUI 0.29.0 and an NVIDIA RTX 5090 using the core MiniMaxH3ImageToVideo node with both first_frame and last_frame connected:

• 768 x 1344
• 124 frames at 24 fps
• 2-step full-resolution smoke test
• res_multistep sampler
• beta scheduler
• UNETLoader with weight_dtype: default

ComfyUI completed model loading, first/last keyframe VAE conditioning, sampling, video/audio VAE decoding, and MP4 encoding successfully. The resulting file contained 124 H.264 frames at 24 fps and 32 kHz stereo AAC audio. The two-step setting verifies execution and is not a production-quality recommendation; use the official 20-step setting for final output.

License and source

Base model: MiniMaxAI/MiniMax-H3

This is a modified derivative and is not an official MiniMax release. This repository includes the upstream MiniMax H3 Community License Agreement and required NOTICE. The upstream license contains territorial restrictions and excludes the European Union, United Kingdom, Republic of Korea, and United States from the applicable territory unless separately authorized by MiniMax. Review the full LICENSE before downloading, using, or redistributing this checkpoint.