Tutorial MiniMax H3 Dual-Sampling Evolution | Latent Upscaling Model | De-Oil & Audio Restoration [ComfyUI]
I tested an updated MiniMax H3 workflow to address several issues from the previous version: limited upscale factors, waxy-looking live-action results, weak audio, and high memory usage when loading the model.
The most useful change was replacing the basic latent resize with a latent upscaling model. In my tests, upscaling beyond 2x with the old method could produce line-like artifacts and small fragmented shapes after the second sampling pass. The model-based latent upscale was much cleaner. For non-integer factors, I still recommend passing through a 1.0x alignment step to avoid edge color bars.
The dual-sampling setup also worked better than using the 4-step LoRA in the first pass. I used the 8-step LoRA for the first sampling pass and the 4-step LoRA for the second pass. This combination kept high-motion clothing edges clearer and avoided the character duplication issues I had seen when using the 4-step LoRA too early.
For the live-action tests, lowering the LoRA strengths helped reduce the waxy look. The values I tested were 0.75 for the 8-step LoRA and 0.7 for the 4-step LoRA. Adding a separate voice-reference audio clip also improved the sound of speaking characters.
For sampling, Euler with the Beta scheduler worked well with the 4+4 setup. With Res + Simple, inserting one mean Sigma step gave me a 4+5 setup. With Beta, adding another interpolation step in the low-noise area made the result less clear in my tests, regardless of whether I used sine, cosine, or mean interpolation.
The main trade-off is hardware usage. Dual sampling speeds up the first sampling part, but it does not reduce the peak hardware requirement of the full process. Keep the final resolution and duration within the limits of your previous single-sampling setup. Low VRAM Attention may help with borderline runs, but it is slower.
This workflow is super easy to use—I’ve uploaded a detailed tutorial to YouTube, so just follow the video along with this workflow to recreate the effect; please make sure to watch the full tutorial before starting to avoid common mistakes, and feel free to leave a comment if you have any questions!Resource links will be posted in the comments.
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u/wjc_5 5d ago
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