--- title: "Caching Acceleration" description: "Compare caching acceleration strategies for diffusion models." tag: "approx" --- SGLang provides two complementary caching strategies for Diffusion Transformer (DiT) models. Both reduce denoising cost by skipping redundant computation, but they operate at different levels. ## Overview SGLang supports two complementary caching approaches:
Strategy Scope Mechanism Best For
Cache-DiT Block-level Skip individual transformer blocks dynamically Advanced, higher speedup
TeaCache Timestep-level Skip entire denoising steps based on L1 similarity Simple, built-in
## Cache-DiT [Cache-DiT](https://github.com/vipshop/cache-dit) provides block-level caching with advanced strategies like DBCache and TaylorSeer. It can achieve up to **1.69x speedup**. See [Cache-DiT](./cache_dit) for detailed configuration. Cache-DiT currently cannot be combined with `--use-fsdp-inference`. Keep FSDP disabled when enabling Cache-DiT, or use other residency/offload controls instead. ### Quick Start ```bash SGLANG_CACHE_DIT_ENABLED=true \ sglang generate --model-path Qwen/Qwen-Image \ --prompt "A beautiful sunset over the mountains" ``` ### Key Features - **DBCache**: Dynamic block-level caching based on residual differences - **TaylorSeer**: Taylor expansion-based calibration for optimized caching - **SCM**: Step-level computation masking for additional speedup ## TeaCache TeaCache (Temporal similarity-based caching) accelerates diffusion inference by detecting when consecutive denoising steps are similar enough to skip computation entirely. See [TeaCache](./teacache) for detailed documentation. ### Quick Overview - Tracks L1 distance between modulated inputs across timesteps - When accumulated distance is below threshold, reuses cached residual - Uses separate positive/negative caches for supported CFG model families ### Supported Models - Wan2.1 - Z-Image - Wan2.2: coefficients are not calibrated yet; enabling TeaCache is accepted but currently no-ops - HunyuanVideo: not supported yet For Flux and Qwen models, TeaCache is automatically disabled when CFG is enabled. ## References - [Cache-DiT Repository](https://github.com/vipshop/cache-dit) - [TeaCache Paper](https://arxiv.org/abs/2411.14324)