CUDA Execution Provider

The CUDA Execution Provider enables hardware accelerated computation on Nvidia CUDA-enabled GPUs.

Contents

• Install
• Requirements
• Build
• Configuration Options
• Samples

Install

Pre-built binaries of ONNX Runtime with CUDA EP are published for most language bindings. Please reference Install ORT.

Requirements

Please reference table below for official GPU packages dependencies for the ONNX Runtime inferencing package. Note that ONNX Runtime Training is aligned with PyTorch CUDA versions; refer to the Training tab on https://onnxruntime.ai/ for supported versions.

Note: Because of CUDA Minor Version Compatibility, Onnx Runtime built with CUDA 11.4 should be compatible with any CUDA 11.x version. Please reference Nvidia CUDA Minor Version Compatibility.

For older versions, please reference the readme and build pages on the release branch.

Build

For build instructions, please see the BUILD page.

Configuration Options

The CUDA Execution Provider supports the following configuration options.

device_id

The device ID.

Default value: 0

gpu_mem_limit

The size limit of the device memory arena in bytes. This size limit is only for the execution provider’s arena. The total device memory usage may be higher. s: max value of C++ size_t type (effectively unlimited)

arena_extend_strategy

The strategy for extending the device memory arena.

Default value: kNextPowerOfTwo

cudnn_conv_algo_search

The type of search done for cuDNN convolution algorithms.

Default value: EXHAUSTIVE

do_copy_in_default_stream

Whether to do copies in the default stream or use separate streams. The recommended setting is true. If false, there are race conditions and possibly better performance.

Default value: true

cudnn_conv_use_max_workspace

Check tuning performance for convolution heavy models for details on what this flag does. This flag is only supported from the V2 version of the provider options struct when used using the C API. The V2 provider options struct can be created using this and updated using this. Please take a look at the sample below for an example.

Default value: 0

Samples

Python

import onnxruntime as ort

model_path = '<path to model>'

providers = [
    ('CUDAExecutionProvider', {
        'device_id': 0,
        'arena_extend_strategy': 'kNextPowerOfTwo',
        'gpu_mem_limit': 2 * 1024 * 1024 * 1024,
        'cudnn_conv_algo_search': 'EXHAUSTIVE',
        'do_copy_in_default_stream': True,
    }),
    'CPUExecutionProvider',
]

session = ort.InferenceSession(model_path, providers=providers)

C/C++

Using legacy provider options struct

OrtSessionOptions* session_options = /* ... */;

OrtCUDAProviderOptions options;
options.device_id = 0;
options.arena_extend_strategy = 0;
options.gpu_mem_limit = 2 * 1024 * 1024 * 1024;
options.cudnn_conv_algo_search = OrtCudnnConvAlgoSearch::EXHAUSTIVE;
options.do_copy_in_default_stream = 1;

SessionOptionsAppendExecutionProvider_CUDA(session_options, &options);

Using V2 provider options struct

OrtCUDAProviderOptionsV2* cuda_options = nullptr;
CreateCUDAProviderOptions(&cuda_options);

std::vector<const char*> keys{"device_id", "gpu_mem_limit", "arena_extend_strategy", "cudnn_conv_algo_search", "do_copy_in_default_stream", "cudnn_conv_use_max_workspace"};
std::vector<const char*> values{"0", "2147483648", "kSameAsRequested", "DEFAULT", "1", "1"};

UpdateCUDAProviderOptions(cuda_options, keys.data(), values.data(), 6);

OrtSessionOptions* session_options = /* ... */;
SessionOptionsAppendExecutionProvider_CUDA_V2(session_options, cuda_options);

// Finally, don't forget to release the provider options
ReleaseCUDAProviderOptions(cuda_options);

C#

var cudaProviderOptions = new OrtCUDAProviderOptions(); // Dispose this finally

var providerOptionsDict = new Dictionary<string, string>();
providerOptionsDict["device_id"] = "0";
providerOptionsDict["gpu_mem_limit"] = "2147483648";
providerOptionsDict["arena_extend_strategy"] = "kSameAsRequested";
providerOptionsDict["cudnn_conv_algo_search"] = "DEFAULT";
providerOptionsDict["do_copy_in_default_stream"] = "1";
providerOptionsDict["cudnn_conv_use_max_workspace"] = "1";

cudaProviderOptions.UpdateOptions(providerOptionsDict);

SessionOptions options = SessionOptions.MakeSessionOptionWithCudaProvider(cudaProviderOptions);  // Dispose this finally