NOTE
Active development on stable-fast
has been paused. I am currently working on a new torch._dynamo
based project targeting new models such as stable-cascade
, SD3
and Sora
like mmodels.
It would be faster and more flexible, as well as supporting more hardware backends rather than CUDA
.
Contact is welcomed.
stable-fast
achieves SOTA inference performance on ALL kinds of diffuser models, even with the latest StableVideoDiffusionPipeline
.
And unlike TensorRT
or AITemplate
, which takes dozens of minutes to compile a model, stable-fast
only takes a few seconds to compile a model.
stable-fast
also supports dynamic shape
, LoRA
and ControlNet
out of the box.
Model | torch | torch.compile | AIT | oneflow | TensorRT | stable-fast |
---|---|---|---|---|---|---|
SD 1.5 (ms) | 1897 | 1510 | 1158 | 1003 | 991 | 995 |
SVD-XT (s) | 83 | 70 | 47 |
NOTE: During benchmarking, TensorRT
is tested with static batch size
and CUDA Graph enabled
while stable-fast
is running with dynamic shape.
stable-fast
is an ultra lightweight inference optimization framework for HuggingFace Diffusers on NVIDIA GPUs.
stable-fast
provides super fast inference optimization by utilizing some key techniques and features:
stable-fast
implements a series of fully-functional and fully-compatible CUDNN convolution fusion operators for all kinds of combinations of Conv + Bias + Add + Act
computation patterns.stable-fast
implements a series of fused GEMM operators that compute with fp16
precision, which is fast than PyTorch's defaults (read & write with fp16
while compute with fp32
).stable-fast
is able to fuse GEGLU(x, W, V, b, c) = GELU(xW + b) ⊗ (xV + c)
into one CUDA kernel.stable-fast
implements a highly optimized fused NHWC GroupNorm + Silu
operator with OpenAI's Triton
, which eliminates the need of memory format permutation operators.stable-fast
improves the torch.jit.trace
interface to make it more proper for tracing complex models. Nearly every part of StableDiffusionPipeline/StableVideoDiffusionPipeline
can be traced and converted to TorchScript. It is more stable than torch.compile
and has a significantly lower CPU overhead than torch.compile
and supports ControlNet and LoRA.stable-fast
can capture the UNet
, VAE
and TextEncoder
into CUDA Graph format, which can reduce the CPU overhead when the batch size is small. This implemention also supports dynamic shape.stable-fast
just uses xformers and makes it compatible with TorchScript.My next goal is to keep stable-fast
as one of the fastest inference optimization frameworks for diffusers
and also
provide both speedup and VRAM reduction for transformers
.
In fact, I already use stable-fast
to optimize LLMs and achieve a significant speedup.
But I still need to do some work to make it more stable and easy to use and provide a stable user interface.
stable-fast
is specialy optimized for HuggingFace Diffusers. It achieves a high performance across many libraries. And it provides a very fast compilation speed within only a few seconds. It is significantly faster than torch.compile
, TensorRT
and AITemplate
in compilation time.stable-fast
works as a plugin framework for PyTorch
. It utilizes existing PyTorch
functionality and infrastructures and is compatible with other acceleration techniques, as well as popular fine-tuning techniques and deployment solutions.stable-fast
is compatible with all kinds of HuggingFace Diffusers
and PyTorch
versions. It is also compatible with ControlNet
and LoRA
. And it even supports the latest StableVideoDiffusionPipeline
out of the box!NOTE: stable-fast
is currently only tested on Linux
and WSL2 in Windows
.
You need to install PyTorch with CUDA support at first (versions from 1.12 to 2.1 are suggested).
I only test stable-fast
with torch>=2.1.0
, xformers>=0.0.22
and triton>=2.1.0
on CUDA 12.1
and Python 3.10
.
Other versions might build and run successfully but that's not guaranteed.
Download the wheel corresponding to your system from the Releases Page and install it with pip3 install <wheel file>
.
Currently both Linux and Windows wheels are available.
# Change cu121 to your CUDA version and <wheel file> to the path of the wheel file.
# And make sure the wheel file is compatible with your PyTorch version.
pip3 install --index-url https://download.pytorch.org/whl/cu121 \
'torch>=2.1.0' 'xformers>=0.0.22' 'triton>=2.1.0' 'diffusers>=0.19.3' \
'<wheel file>'
# Make sure you have CUDNN/CUBLAS installed.
# https://developer.nvidia.com/cudnn
# https://developer.nvidia.com/cublas
# Install PyTorch with CUDA and other packages at first.
# Windows user: Triton might be not available, you could skip it.
# NOTE: 'wheel' is required or you will meet `No module named 'torch'` error when building.
pip3 install wheel 'torch>=2.1.0' 'xformers>=0.0.22' 'triton>=2.1.0' 'diffusers>=0.19.3'
# (Optional) Makes the build much faster.
pip3 install ninja
# Set TORCH_CUDA_ARCH_LIST if running and building on different GPU types.
# You can also install the latest stable release from PyPI.
# pip3 install -v -U stable-fast
pip3 install -v -U git+https://github.com/chengzeyi/stable-fast.git@main#egg=stable-fast
# (this can take dozens of minutes)
NOTE: Any usage outside sfast.compilers
is not guaranteed to be backward compatible.
NOTE: To get the best performance, xformers
and OpenAI's triton>=2.1.0
need to be installed and enabled.
You might need to build xformers
from source to make it compatible with your PyTorch
.
stable-fast
is able to optimize StableDiffusionPipeline
and StableDiffusionPipelineXL
directly.
import time
import torch
from diffusers import (StableDiffusionPipeline,
EulerAncestralDiscreteScheduler)
from sfast.compilers.diffusion_pipeline_compiler import (compile,
CompilationConfig)
def load_model():
model = StableDiffusionPipeline.from_pretrained(
'runwayml/stable-diffusion-v1-5',
torch_dtype=torch.float16)
model.scheduler = EulerAncestralDiscreteScheduler.from_config(
model.scheduler.config)
model.safety_checker = None
model.to(torch.device('cuda'))
return model
model = load_model()
config = CompilationConfig.Default()
# xformers and Triton are suggested for achieving best performance.
try:
import xformers
config.enable_xformers = True
except ImportError:
print('xformers not installed, skip')
try:
import triton
config.enable_triton = True
except ImportError:
print('Triton not installed, skip')
# CUDA Graph is suggested for small batch sizes and small resolutions to reduce CPU overhead.
# But it can increase the amount of GPU memory used.
# For StableVideoDiffusionPipeline it is not needed.
config.enable_cuda_graph = True
model = compile(model, config)
kwarg_inputs = dict(
prompt=
'(masterpiece:1,2), best quality, masterpiece, best detailed face, a beautiful girl',
height=512,
width=512,
num_inference_steps=30,
num_images_per_prompt=1,
)
# NOTE: Warm it up.
# The initial calls will trigger compilation and might be very slow.
# After that, it should be very fast.
for _ in range(3):
output_image = model(**kwarg_inputs).images[0]
# Let's see it!
# Note: Progress bar might work incorrectly due to the async nature of CUDA.
begin = time.time()
output_image = model(**kwarg_inputs).images[0]
print(f'Inference time: {time.time() - begin:.3f}s')
# Let's view it in terminal!
from sfast.utils.term_image import print_image
print_image(output_image, max_width=80)
Refer to examples/optimize_stable_diffusion_pipeline.py for more details.
You can check this Colab to see how it works on T4 GPU:
stable-fast
is able to optimize the newest latent consistency model
pipeline and achieve a significant speedup.
Refer to examples/optimize_lcm_pipeline.py for more details about how to optimize normal SD model with LCM LoRA. Refer to examples/optimize_lcm_pipeline.py for more details about how to optimize the standalone LCM model.
stable-fast
is able to optimize the newest StableVideoDiffusionPipeline
and achieve a 2x
speedup
Refer to examples/optimize_stable_video_diffusion_pipeline.py for more details
Switching LoRA dynamically is supported but you need to do some extra work.
It is possible because the compiled graph and CUDA Graph
share the same
underlaying data (pointers) with the original UNet model. So all you need to do
is to update the original UNet model's parameters inplace.
The following code assumes you have already load a LoRA and compiled the model, and you want to switch to another LoRA.
If you don't enable CUDA graph and keep preserve_parameters = True
, things could be much easier.
The following code might not even be needed.
# load_state_dict with assign=True requires torch >= 2.1.0
def update_state_dict(dst, src):
for key, value in src.items():
# Do inplace copy.
# As the traced forward function shares the same underlaying data (pointers),
# this modification will be reflected in the traced forward function.
dst[key].copy_(value)
# Switch "another" LoRA into UNet
def switch_lora(unet, lora):
# Store the original UNet parameters
state_dict = unet.state_dict()
# Load another LoRA into unet
unet.load_attn_procs(lora)
# Inplace copy current UNet parameters to the original unet parameters
update_state_dict(state_dict, unet.state_dict())
# Load the original UNet parameters back.
# We use assign=True because we still want to hold the references
# of the original UNet parameters
unet.load_state_dict(state_dict, assign=True)
switch_lora(compiled_model.unet, lora_b_path)
stable-fast
extends PyTorch's quantize_dynamic
functionality and provides a dynamically quantized linear operator on CUDA backend.
By enabling it, you could get a slight VRAM reduction for diffusers
and significant VRAM reduction for transformers
,
and cound get a potential speedup (not always).
For SD XL
, it is expected to see VRAM reduction of 2GB
with an image size of 1024x1024
.
def quantize_unet(m):
from diffusers.utils import USE_PEFT_BACKEND
assert USE_PEFT_BACKEND
m = torch.quantization.quantize_dynamic(m, {torch.nn.Linear},
dtype=torch.qint8,
inplace=True)
return m
model.unet = quantize_unet(model.unet)
if hasattr(model, 'controlnet'):
model.controlnet = quantize_unet(model.controlnet)
Refer to examples/optimize_stable_diffusion_pipeline.py for more details.
# TCMalloc is highly suggested to reduce CPU overhead
# https://github.com/google/tcmalloc
LD_PRELOAD=/path/to/libtcmalloc.so python3 ...
import packaging.version
import torch
if packaging.version.parse(torch.__version__) >= packaging.version.parse('1.12.0'):
torch.backends.cuda.matmul.allow_tf32 = True
Performance varies very greatly across different hardware/software/platform/driver configurations.
It is very hard to benchmark accurately. And preparing the environment for benchmarking is also a hard job.
I have tested on some platforms before but the results may still be inaccurate.
Note that when benchmarking, the progress bar showed by tqdm
may be inaccurate because of the asynchronous nature of CUDA.
To solve this problem, I use CUDA Event
to measure the speed of iterations per second accurately.
stable-fast
is expected to work better on newer GPUs and newer CUDA versions.
On older GPUs, the performance increase might be limited.
During benchmarking, the progress bar might work incorrectly because of the asynchronous nature of CUDA.
This is my personal gaming PC😄. It has a more powerful CPU than those from cloud server providers.
Framework | SD 1.5 | SD XL (1024x1024) | SD 1.5 ControlNet |
---|---|---|---|
Vanilla PyTorch (2.1.0) | 29.5 it/s | 4.6 it/s | 19.7 it/s |
torch.compile (2.1.0, max-autotune) | 40.0 it/s | 6.1 it/s | 21.8 it/s |
AITemplate | 44.2 it/s | ||
OneFlow | 53.6 it/s | ||
AUTO1111 WebUI | 17.2 it/s | 3.6 it/s | |
AUTO1111 WebUI (with SDPA) | 24.5 it/s | 4.3 it/s | |
TensorRT (AUTO1111 WebUI) | 40.8 it/s | ||
TensorRT Official Demo | 52.6 it/s | ||
stable-fast (with xformers & Triton) | 51.6 it/s | 9.1 it/s | 36.7 it/s |
Thanks for @Consceleratus and @harishp's help, I have tested speed on H100.
Framework | SD 1.5 | SD XL (1024x1024) | SD 1.5 ControlNet |
---|---|---|---|
Vanilla PyTorch (2.1.0) | 54.5 it/s | 14.9 it/s | 35.8 it/s |
torch.compile (2.1.0, max-autotune) | 66.0 it/s | 18.5 it/s | |
stable-fast (with xformers & Triton) | 104.6 it/s | 21.6 it/s | 72.6 it/s |
Thanks for @SuperSecureHuman and @jon-chuang's help, benchmarking on A100 is available now.
Framework | SD 1.5 | SD XL (1024x1024) | SD 1.5 ControlNet |
---|---|---|---|
Vanilla PyTorch (2.1.0) | 35.6 it/s | 8.7 it/s | 25.1 it/s |
torch.compile (2.1.0, max-autotune) | 41.9 it/s | 10.0 it/s | |
stable-fast (with xformers & Triton) | 61.8 it/s | 11.9 it/s | 41.1 it/s |
Model | Supported |
---|---|
Hugging Face Diffusers (1.5/2.1/XL) | Yes |
With ControlNet | Yes |
With LoRA | Yes |
Latent Consistency Model | Yes |
SDXL Turbo | Yes |
Stable Video Diffusion | Yes |
Functionality | Supported |
---|---|
Dynamic Shape | Yes |
Text to Image | Yes |
Image to Image | Yes |
Image Inpainting | Yes |
UI Framework | Supported | Link |
---|---|---|
AUTOMATIC1111 | WIP | |
SD Next | Yes | SD Next |
ComfyUI | Yes | ComfyUI_stable_fast |
Operating System | Supported |
---|---|
Linux | Yes |
Windows | Yes |
Windows WSL | Yes |
Refer to doc/troubleshooting.md for more details.
And you can join the Discord Channel to ask for help.