MiniMax H3 in ComfyUI: compare video upscalers

This ComfyUI tutorial compares three ways to upscale MiniMax H3 video on your own hardware. The presenter starts with 0.2 MP clips so prompt and seed experiments take less time, then applies a separate upscale pass.

In the presenter's tests, Ultimate Upscale adds more detail but can change the source noticeably. The suggested settings are four steps, a linear quadratic scheduler and denoise around 0.45. One example reaches 1216 × 704. Latent Upscaler 3D preserves more of the original appearance with a beta scheduler and can use two steps. Its controls accept a scale multiplier, target dimensions or megapixel value, with a force-unload option to reduce VRAM use.

SeedVR2, shown in INT8 format, sharpens the result while adding less detail in these examples. The presenter also applies it after another upscaler, but warns that large scale factors can demand substantial resources.

The workflow section covers reloading an extended video by file path and passing the selected dimensions into later extensions. The presenter reports noticeable changes when upscaling extensions separately, and replaces the audio latent produced by the 3D upscale with the original audio. Sparse linear attention settings round out the local AI workflow. This builds on earlier tutorials rather than covering installation from scratch.