GPU acceleration

This document provides a complete instruction on using GPU acceleration with Concrete ML.

Concrete ML support compiling both built-in and custom models using a CUDA-accelerated backend. However, once a model is compiled for CUDA, executing it on a non-CUDA-enabled machine will raise an error.

Support

Feature	Built-in models	Deep NNs and LLMs	Deployment	DataFrame
GPU support	✅	✅	✅	❌

When compiling a model for GPU, the model is assigned GPU-specific crypto-system parameters. These parameters are more constrained than the CPU-specific ones. As a result, the Concrete compiler may have difficulty finding suitable GPU-compatible crypto-parameters for some models, leading to a NoParametersFound error.

Performance

On high-end GPUs like V100, A100, or H100, the performance gains range from 1x to 10x compared to a desktop CPU.

When compared to a high-end server CPUs(64-core or 96-core), the speed-up is typically around 1x to 3x.

On consumer grade GPUs such as GTX40xx or GTX30xx, there may be little speedup or even a slowdown compared to execution on a desktop CPU.

Prerequisites

Built-in models and deep NNs

This section pertains to models that are compiled using the sklearn-style built-in model classes or that are compiled using compile_torch_model or compile_brevitas_qat_model.

To use the CUDA-enabled backend, install the GPU-enabled Concrete compiler:

pip install --extra-index-url https://pypi.zama.ai/gpu concrete-python

If you already have an existing version of concrete-python installed, it will not be re-installed automatically. In that case, manually uninstall the current version and then install the GPU-enabled version:

pip uninstall concrete-python
pip install --extra-index-url https://pypi.zama.ai/gpu concrete-python

To switch back to the CPU-only version of the compiler, change the index-url to the CPU-only repository or remove the index-url parameter:

pip uninstall concrete-python
pip install --extra-index-url https://pypi.zama.ai/cpu concrete-python

Checking GPU can be enabled

To check if the CUDA acceleration is available, use the following helper functions from concrete-python:

import concrete.compiler; 
print("GPU enabled: ", concrete.compiler.check_gpu_enabled())
print("GPU available: ", concrete.compiler.check_gpu_available())

Usage

To compile a model for CUDA, simply supply the device='cuda' argument to its compilation function:

• For built-in models, use .compile function.

• For custom models, use eithercompile_torch_model or compile_brevitas_qat_model.

LLMs

This section pertains to models that are compiled with HybridFHEModel.

The models compiled as described in the LLM section will use GPU acceleration if a GPU is available on the machine where the models are executed. No specific compilation configuration is required to enable GPU execution for these models.