Benchmarking MiniMax H3: Doubling Video Length Nearly Triples Render Time

jtreminio · reddit · 2026-08-05

A developer benchmarked the MiniMax H3 video generation model, revealing a non-linear growth pattern in rendering time: doubling the video length nearly triples the render time. For instance, a 5-second clip takes 2 minutes, while a 30-second clip takes 43 minutes.

The author explains the underlying mechanism: H3 chops video into a grid, and due to the $O(n^2)$ complexity of the attention mechanism, every second added increases the computational cost of all previous frames. This means the marginal rendering cost per second of video continuously rises.

Related event: MiniMax H3 Video Generation Shows Non-linear Time Scaling(2 posts)→

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