MC-Sparse: Deconstructing and Closing the Dense-Sparse Attention Gap in Diffusion Transformers
Sparse attention is a primary approach to reducing the latency of diffusion transformers in long-sequence generation tasks, such as video and high-resolution 3D asset generation.
ProofPaper ↗
Key points
- Through controlled oracle comparisons, we trace this degradation to three sources: constraints imposed by token grouping, inaccurate interaction selection, and the attention contributions lost when tokens are discarded.
- Guided by this analysis, we propose Meta-Cached Sparse Attention (MC-Sparse), a training-free framework that selects individual key-value (KV) tokens while organizing similar queries into tile-aligned groups for efficient GPU execution.
- MC-Sparse caches metadata comprising query groups, KV indices selected using exact attention probabilities, and residuals between dense and sparse attention outputs, and reuses them across subsequent denoising steps.
- Across video and 3D generation models, MC-Sparse achieves higher fidelity to dense-attention outputs and larger denoising speedups than existing sparse-attention baselines, without visible quality degradation.
Sources (1)
- [1]MC-Sparse: Deconstructing and Closing the Dense-Sparse Attention Gap in Diffusion TransformersHugging Face Daily Papers · Oct 5, 12:00 AM
Sparse attention is a primary approach to reducing the latency of diffusion transformers in long-sequence generation tasks, such as video and high-resolution 3D asset generation.
Through controlled oracle comparisons, we trace this degradation to three sources: constraints imposed by token grouping, inaccurate interaction selection, and the attention contributions lost when tokens are discarded.
Extractive summary: sentences quoted from the sources.
Before this
- Sep 29, 2026Sonnet 5.5 is worth a try
- Aug 10, 2026vllm-project/vllm v0.27.0
- Aug 10, 2026huggingface/transformers v5.15.0: Release: v5.15.0
- Jul 11, 2026vllm-project/vllm v0.25.0
- Jun 15, 2026vllm-project/vllm v0.23.0
- Jun 12, 2026huggingface/transformers v5.12.0: Release v5.12.0