Plug-and-Play Fidelity Optimization for Diffusion Transformer Acceleration via Cumulative Error Minimization
Tong Shao, Yusen Fu, Guoying Sun, Jingde Kong, Zhuotao Tian, Jingyong Su
TL;DR
Diffusion Transformer models suffer slow inference due to sequential denoising, and fixed caching strategies fail to adapt to complex denoising dynamics. The paper proposes Cumulative Error Minimization (CEM), a training-free plug-in that builds an offline prior of caching error as a function of timestep $t$ and cache interval $n$, then uses dynamic programming to minimize the cumulative error under an acceleration budget $N_c$. CEM is model-agnostic, compatible with existing error-correction and quantized DiTs, and requires no online overhead beyond a precomputed error matrix. Across multiple text-to-image, text-to-video, and class-to-image tasks, CEM consistently improves fidelity for eight generation models and a quantized DiT, while preserving or enhancing acceleration, demonstrating a practical path to robust, high-fidelity, fast diffusion generation.
Abstract
Although Diffusion Transformer (DiT) has emerged as a predominant architecture for image and video generation, its iterative denoising process results in slow inference, which hinders broader applicability and development. Caching-based methods achieve training-free acceleration, while suffering from considerable computational error. Existing methods typically incorporate error correction strategies such as pruning or prediction to mitigate it. However, their fixed caching strategy fails to adapt to the complex error variations during denoising, which limits the full potential of error correction. To tackle this challenge, we propose a novel fidelity-optimization plugin for existing error correction methods via cumulative error minimization, named CEM. CEM predefines the error to characterize the sensitivity of model to acceleration jointly influenced by timesteps and cache intervals. Guided by this prior, we formulate a dynamic programming algorithm with cumulative error approximation for strategy optimization, which achieves the caching error minimization, resulting in a substantial improvement in generation fidelity. CEM is model-agnostic and exhibits strong generalization, which is adaptable to arbitrary acceleration budgets. It can be seamlessly integrated into existing error correction frameworks and quantized models without introducing any additional computational overhead. Extensive experiments conducted on nine generation models and quantized methods across three tasks demonstrate that CEM significantly improves generation fidelity of existing acceleration models, and outperforms the original generation performance on FLUX.1-dev, PixArt-$α$, StableDiffusion1.5 and Hunyuan. The code will be made publicly available.
