arXiv Machine Learning By Chuyu Hu, Huanran Chen, Shitong Shao, Yinpeng Dong

Large Diffusion Models Need More Than EMA

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The paper examines whether exponential moving average (EMA) is uniquely suited for training large diffusion models or if other optimization strategies can be more effective. It shows that constant‑step averaging has inherent limitations, while learning‑rate decay and Schedule‑Free optimization provide stronger convergence guarantees under nonconvex assumptions. Empirical results indicate that combining decay with EMA yields modest gains, but Schedule‑Free consistently outperforms EMA alone, reducing parameter variability while maintaining late‑stage progress and improving generation quality across multiple diffusion settings.

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