SALAD: Achieve High-Sparsity Attention via Efficient Linear Attention Tuning for Video Diffusion Transformer

Diffusion Transformers have demonstrated remarkable performance in video generation. However, their long input sequences incur substantial latency due to the quadratic complexity of full attention. Various sparse attention mechanisms have been proposed. Training-free approaches are limited to moderate sparsity and thus yield only modest acceleration, whereas training-based methods can reach much higher sparsity but demand substantial data and computation. In this work, we propose SALAD, introducing a lightweight linear attention branch in parallel with the sparse attention. Leveraging a Multi-level Static-Dynamic Scaling Strategy to balance the two branches, our method attains up to 90% sparsity and 1.52-2.03x inference speedup across different models and sequence lengths, while maintaining generation quality comparable to the full attention baseline. Moreover, our finetuning process is highly efficient, requiring only 2,000 video samples, fewer than 1,600 training steps, and no more than 30 GPU hours with a batch size of 8.