|
| 1 | +## CacheDiT |
| 2 | + |
| 3 | +CacheDiT is a unified, flexible, and training-free cache acceleration framework designed to support nearly all Diffusers' DiT-based pipelines. It provides a unified cache API that supports automatic block adapter, DBCache, and more. |
| 4 | + |
| 5 | +To learn more, refer to the [CacheDiT](https://github.com/vipshop/cache-dit) repository. |
| 6 | + |
| 7 | +Install a stable release of CacheDiT from PyPI or you can install the latest version from GitHub. |
| 8 | + |
| 9 | +<hfoptions id="install"> |
| 10 | +<hfoption id="PyPI"> |
| 11 | + |
| 12 | +```bash |
| 13 | +pip3 install -U cache-dit |
| 14 | +``` |
| 15 | + |
| 16 | +</hfoption> |
| 17 | +<hfoption id="source"> |
| 18 | + |
| 19 | +```bash |
| 20 | +pip3 install git+https://github.com/vipshop/cache-dit.git |
| 21 | +``` |
| 22 | + |
| 23 | +</hfoption> |
| 24 | +</hfoptions> |
| 25 | + |
| 26 | +Run the command below to view supported DiT pipelines. |
| 27 | + |
| 28 | +```python |
| 29 | +>>> import cache_dit |
| 30 | +>>> cache_dit.supported_pipelines() |
| 31 | +(30, ['Flux*', 'Mochi*', 'CogVideoX*', 'Wan*', 'HunyuanVideo*', 'QwenImage*', 'LTX*', 'Allegro*', |
| 32 | +'CogView3Plus*', 'CogView4*', 'Cosmos*', 'EasyAnimate*', 'SkyReelsV2*', 'StableDiffusion3*', |
| 33 | +'ConsisID*', 'DiT*', 'Amused*', 'Bria*', 'Lumina*', 'OmniGen*', 'PixArt*', 'Sana*', 'StableAudio*', |
| 34 | +'VisualCloze*', 'AuraFlow*', 'Chroma*', 'ShapE*', 'HiDream*', 'HunyuanDiT*', 'HunyuanDiTPAG*']) |
| 35 | +``` |
| 36 | + |
| 37 | +For a complete benchmark, please refer to [Benchmarks](https://github.com/vipshop/cache-dit/blob/main/bench/). |
| 38 | + |
| 39 | + |
| 40 | +## Unified Cache API |
| 41 | + |
| 42 | +CacheDiT works by matching specific input/output patterns as shown below. |
| 43 | + |
| 44 | + |
| 45 | + |
| 46 | +Call the `enable_cache()` function on a pipeline to enable cache acceleration. This function is the entry point to many of CacheDiT's features. |
| 47 | + |
| 48 | +```python |
| 49 | +import cache_dit |
| 50 | +from diffusers import DiffusionPipeline |
| 51 | + |
| 52 | +# Can be any diffusion pipeline |
| 53 | +pipe = DiffusionPipeline.from_pretrained("Qwen/Qwen-Image") |
| 54 | + |
| 55 | +# One-line code with default cache options. |
| 56 | +cache_dit.enable_cache(pipe) |
| 57 | + |
| 58 | +# Just call the pipe as normal. |
| 59 | +output = pipe(...) |
| 60 | + |
| 61 | +# Disable cache and run original pipe. |
| 62 | +cache_dit.disable_cache(pipe) |
| 63 | +``` |
| 64 | + |
| 65 | +## Automatic Block Adapter |
| 66 | + |
| 67 | +For custom or modified pipelines or transformers not included in Diffusers, use the `BlockAdapter` in `auto` mode or via manual configuration. Please check the [BlockAdapter](https://github.com/vipshop/cache-dit/blob/main/docs/User_Guide.md#automatic-block-adapter) docs for more details. Refer to [Qwen-Image w/ BlockAdapter](https://github.com/vipshop/cache-dit/blob/main/examples/adapter/run_qwen_image_adapter.py) as an example. |
| 68 | + |
| 69 | + |
| 70 | +```python |
| 71 | +from cache_dit import ForwardPattern, BlockAdapter |
| 72 | + |
| 73 | +# Use 🔥BlockAdapter with `auto` mode. |
| 74 | +cache_dit.enable_cache( |
| 75 | + BlockAdapter( |
| 76 | + # Any DiffusionPipeline, Qwen-Image, etc. |
| 77 | + pipe=pipe, auto=True, |
| 78 | + # Check `📚Forward Pattern Matching` documentation and hack the code of |
| 79 | + # of Qwen-Image, you will find that it has satisfied `FORWARD_PATTERN_1`. |
| 80 | + forward_pattern=ForwardPattern.Pattern_1, |
| 81 | + ), |
| 82 | +) |
| 83 | + |
| 84 | +# Or, manually setup transformer configurations. |
| 85 | +cache_dit.enable_cache( |
| 86 | + BlockAdapter( |
| 87 | + pipe=pipe, # Qwen-Image, etc. |
| 88 | + transformer=pipe.transformer, |
| 89 | + blocks=pipe.transformer.transformer_blocks, |
| 90 | + forward_pattern=ForwardPattern.Pattern_1, |
| 91 | + ), |
| 92 | +) |
| 93 | +``` |
| 94 | + |
| 95 | +Sometimes, a Transformer class will contain more than one transformer `blocks`. For example, FLUX.1 (HiDream, Chroma, etc) contains `transformer_blocks` and `single_transformer_blocks` (with different forward patterns). The BlockAdapter is able to detect this hybrid pattern type as well. |
| 96 | +Refer to [FLUX.1](https://github.com/vipshop/cache-dit/blob/main/examples/adapter/run_flux_adapter.py) as an example. |
| 97 | + |
| 98 | +```python |
| 99 | +# For diffusers <= 0.34.0, FLUX.1 transformer_blocks and |
| 100 | +# single_transformer_blocks have different forward patterns. |
| 101 | +cache_dit.enable_cache( |
| 102 | + BlockAdapter( |
| 103 | + pipe=pipe, # FLUX.1, etc. |
| 104 | + transformer=pipe.transformer, |
| 105 | + blocks=[ |
| 106 | + pipe.transformer.transformer_blocks, |
| 107 | + pipe.transformer.single_transformer_blocks, |
| 108 | + ], |
| 109 | + forward_pattern=[ |
| 110 | + ForwardPattern.Pattern_1, |
| 111 | + ForwardPattern.Pattern_3, |
| 112 | + ], |
| 113 | + ), |
| 114 | +) |
| 115 | +``` |
| 116 | + |
| 117 | +This also works if there is more than one transformer (namely `transformer` and `transformer_2`) in its structure. Refer to [Wan 2.2 MoE](https://github.com/vipshop/cache-dit/blob/main/examples/pipeline/run_wan_2.2.py) as an example. |
| 118 | + |
| 119 | +## Patch Functor |
| 120 | + |
| 121 | +For any pattern not included in CacheDiT, use the Patch Functor to convert the pattern into a known pattern. You need to subclass the Patch Functor and may also need to fuse the operations within the blocks for loop into block `forward`. After implementing a Patch Functor, set the `patch_functor` property in `BlockAdapter`. |
| 122 | + |
| 123 | + |
| 124 | + |
| 125 | +Some Patch Functors are already provided in CacheDiT, [HiDreamPatchFunctor](https://github.com/vipshop/cache-dit/blob/main/src/cache_dit/cache_factory/patch_functors/functor_hidream.py), [ChromaPatchFunctor](https://github.com/vipshop/cache-dit/blob/main/src/cache_dit/cache_factory/patch_functors/functor_chroma.py), etc. |
| 126 | + |
| 127 | +```python |
| 128 | +@BlockAdapterRegistry.register("HiDream") |
| 129 | +def hidream_adapter(pipe, **kwargs) -> BlockAdapter: |
| 130 | + from diffusers import HiDreamImageTransformer2DModel |
| 131 | + from cache_dit.cache_factory.patch_functors import HiDreamPatchFunctor |
| 132 | + |
| 133 | + assert isinstance(pipe.transformer, HiDreamImageTransformer2DModel) |
| 134 | + return BlockAdapter( |
| 135 | + pipe=pipe, |
| 136 | + transformer=pipe.transformer, |
| 137 | + blocks=[ |
| 138 | + pipe.transformer.double_stream_blocks, |
| 139 | + pipe.transformer.single_stream_blocks, |
| 140 | + ], |
| 141 | + forward_pattern=[ |
| 142 | + ForwardPattern.Pattern_0, |
| 143 | + ForwardPattern.Pattern_3, |
| 144 | + ], |
| 145 | + # NOTE: Setup your custom patch functor here. |
| 146 | + patch_functor=HiDreamPatchFunctor(), |
| 147 | + **kwargs, |
| 148 | + ) |
| 149 | +``` |
| 150 | + |
| 151 | +Finally, you can call the `cache_dit.summary()` function on a pipeline after its completed inference to get the cache acceleration details. |
| 152 | + |
| 153 | +```python |
| 154 | +stats = cache_dit.summary(pipe) |
| 155 | +``` |
| 156 | + |
| 157 | +```python |
| 158 | +⚡️Cache Steps and Residual Diffs Statistics: QwenImagePipeline |
| 159 | + |
| 160 | +| Cache Steps | Diffs Min | Diffs P25 | Diffs P50 | Diffs P75 | Diffs P95 | Diffs Max | |
| 161 | +|-------------|-----------|-----------|-----------|-----------|-----------|-----------| |
| 162 | +| 23 | 0.045 | 0.084 | 0.114 | 0.147 | 0.241 | 0.297 | |
| 163 | +``` |
| 164 | + |
| 165 | +## DBCache: Dual Block Cache |
| 166 | + |
| 167 | + |
| 168 | + |
| 169 | +DBCache (Dual Block Caching) supports different configurations of compute blocks (F8B12, etc.) to enable a balanced trade-off between performance and precision. |
| 170 | +- Fn_compute_blocks: Specifies that DBCache uses the **first n** Transformer blocks to fit the information at time step t, enabling the calculation of a more stable L1 diff and delivering more accurate information to subsequent blocks. |
| 171 | +- Bn_compute_blocks: Further fuses approximate information in the **last n** Transformer blocks to enhance prediction accuracy. These blocks act as an auto-scaler for approximate hidden states that use residual cache. |
| 172 | + |
| 173 | + |
| 174 | +```python |
| 175 | +import cache_dit |
| 176 | +from diffusers import FluxPipeline |
| 177 | + |
| 178 | +pipe_or_adapter = FluxPipeline.from_pretrained( |
| 179 | + "black-forest-labs/FLUX.1-dev", |
| 180 | + torch_dtype=torch.bfloat16, |
| 181 | +).to("cuda") |
| 182 | + |
| 183 | +# Default options, F8B0, 8 warmup steps, and unlimited cached |
| 184 | +# steps for good balance between performance and precision |
| 185 | +cache_dit.enable_cache(pipe_or_adapter) |
| 186 | + |
| 187 | +# Custom options, F8B8, higher precision |
| 188 | +from cache_dit import BasicCacheConfig |
| 189 | + |
| 190 | +cache_dit.enable_cache( |
| 191 | + pipe_or_adapter, |
| 192 | + cache_config=BasicCacheConfig( |
| 193 | + max_warmup_steps=8, # steps do not cache |
| 194 | + max_cached_steps=-1, # -1 means no limit |
| 195 | + Fn_compute_blocks=8, # Fn, F8, etc. |
| 196 | + Bn_compute_blocks=8, # Bn, B8, etc. |
| 197 | + residual_diff_threshold=0.12, |
| 198 | + ), |
| 199 | +) |
| 200 | +``` |
| 201 | +Check the [DBCache](https://github.com/vipshop/cache-dit/blob/main/docs/DBCache.md) and [User Guide](https://github.com/vipshop/cache-dit/blob/main/docs/User_Guide.md#dbcache) docs for more design details. |
| 202 | + |
| 203 | +## TaylorSeer Calibrator |
| 204 | + |
| 205 | +The [TaylorSeers](https://huggingface.co/papers/2503.06923) algorithm further improves the precision of DBCache in cases where the cached steps are large (Hybrid TaylorSeer + DBCache). At timesteps with significant intervals, the feature similarity in diffusion models decreases substantially, significantly harming the generation quality. |
| 206 | + |
| 207 | +TaylorSeer employs a differential method to approximate the higher-order derivatives of features and predict features in future timesteps with Taylor series expansion. The TaylorSeer implemented in CacheDiT supports both hidden states and residual cache types. F_pred can be a residual cache or a hidden-state cache. |
| 208 | + |
| 209 | +```python |
| 210 | +from cache_dit import BasicCacheConfig, TaylorSeerCalibratorConfig |
| 211 | + |
| 212 | +cache_dit.enable_cache( |
| 213 | + pipe_or_adapter, |
| 214 | + # Basic DBCache w/ FnBn configurations |
| 215 | + cache_config=BasicCacheConfig( |
| 216 | + max_warmup_steps=8, # steps do not cache |
| 217 | + max_cached_steps=-1, # -1 means no limit |
| 218 | + Fn_compute_blocks=8, # Fn, F8, etc. |
| 219 | + Bn_compute_blocks=8, # Bn, B8, etc. |
| 220 | + residual_diff_threshold=0.12, |
| 221 | + ), |
| 222 | + # Then, you can use the TaylorSeer Calibrator to approximate |
| 223 | + # the values in cached steps, taylorseer_order default is 1. |
| 224 | + calibrator_config=TaylorSeerCalibratorConfig( |
| 225 | + taylorseer_order=1, |
| 226 | + ), |
| 227 | +) |
| 228 | +``` |
| 229 | + |
| 230 | +> [!TIP] |
| 231 | +> The `Bn_compute_blocks` parameter of DBCache can be set to `0` if you use TaylorSeer as the calibrator for approximate hidden states. DBCache's `Bn_compute_blocks` also acts as a calibrator, so you can choose either `Bn_compute_blocks` > 0 or TaylorSeer. We recommend using the configuration scheme of TaylorSeer + DBCache FnB0. |
| 232 | +
|
| 233 | +## Hybrid Cache CFG |
| 234 | + |
| 235 | +CacheDiT supports caching for CFG (classifier-free guidance). For models that fuse CFG and non-CFG into a single forward step, or models that do not include CFG in the forward step, please set `enable_separate_cfg` parameter to `False (default, None)`. Otherwise, set it to `True`. |
| 236 | + |
| 237 | +```python |
| 238 | +from cache_dit import BasicCacheConfig |
| 239 | + |
| 240 | +cache_dit.enable_cache( |
| 241 | + pipe_or_adapter, |
| 242 | + cache_config=BasicCacheConfig( |
| 243 | + ..., |
| 244 | + # For example, set it as True for Wan 2.1, Qwen-Image |
| 245 | + # and set it as False for FLUX.1, HunyuanVideo, etc. |
| 246 | + enable_separate_cfg=True, |
| 247 | + ), |
| 248 | +) |
| 249 | +``` |
| 250 | + |
| 251 | +## torch.compile |
| 252 | + |
| 253 | +CacheDiT is designed to work with torch.compile for even better performance. Call `torch.compile` after enabling the cache. |
| 254 | + |
| 255 | + |
| 256 | +```python |
| 257 | +cache_dit.enable_cache(pipe) |
| 258 | + |
| 259 | +# Compile the Transformer module |
| 260 | +pipe.transformer = torch.compile(pipe.transformer) |
| 261 | +``` |
| 262 | + |
| 263 | +If you're using CacheDiT with dynamic input shapes, consider increasing the `recompile_limit` of `torch._dynamo`. Otherwise, the `recompile_limit` error may be triggered, causing the module to fall back to eager mode. |
| 264 | + |
| 265 | +```python |
| 266 | +torch._dynamo.config.recompile_limit = 96 # default is 8 |
| 267 | +torch._dynamo.config.accumulated_recompile_limit = 2048 # default is 256 |
| 268 | +``` |
| 269 | + |
| 270 | +Please check [perf.py](https://github.com/vipshop/cache-dit/blob/main/bench/perf.py) for more details. |
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