onnxruntime/docs/execution_providers/OpenVINO-ExecutionProvider.md

OpenVINO Execution Provider

OpenVINO Execution Provider enables deep learning inference on Intel CPUs, Intel integrated GPUs and Intel^® Movidius^TM Vision Processing Units (VPUs). Please refer to this page for details on the Intel hardware supported.

Build

For build instructions, please see the BUILD page.

Runtime configuration options

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OpenVINO EP can be configured with certain options at runtime that control the behavior of the EP. These options can be set as key-value pairs as below:-

Python API

Key-Value pairs for config options can be set using the Session.set_providers API as follows:-

session = onnxruntime.InferenceSession(<path_to_model_file>, options)
session.set_providers(['OpenVINOExecutionProviders'], [{Key1 : Value1, Key2 : Value2, ...}])

Note that this causes the InferenceSession to be re-initialized, which may cause model recompilation and hardware re-initialization

C/C++ API

All the options (key-value pairs) need to be concantenated into a string as shown below and passed to OrtSessionOptionsAppendExecutionProviderEx_OpenVINO() API as shown below:-

std::string settings_str;
settings_str.append("Key1|Value1\n");
settings_str.append("Key2|Value2\n");
settings_str.append("Key3|Value3\n");
Ort::ThrowOnError(OrtSessionOptionsAppendExecutionProviderEx_OpenVINO(sf, settings_str));

Available configuration options

The following table lists all the available configuratoin optoins and the Key-Value pairs to set them:-

Key	Key type	Allowable Values	Value type	Description
device_type	string	CPU_FP32, GPU_FP32, GPU_FP16, MYRIAD_FP16, VAD-M_FP16, VAD-M_FP32	string	Overrides the accelerator hardware type and precision with these values at runtime. If this option is not explicitly set, default hardware and precision specified during build time is used.
device_id	string	Any valid OpenVINO device ID	string	Selects a particular hardware device for inference. The list of valid OpenVINO device ID's available on a platform can be obtained either by Python API (onnxruntime.capi._pybind_state.get_available_openvino_device_ids()) or by OpenVINO C/C++ API. If this option is not explicitly set, an arbitrary free device will be automatically selected by OpenVINO runtime.
enable_vpu_fast_recompile	string	True/False	boolean	This option is only available for MYRIAD_FP16 VPU devices. During initialization of the VPU device with compiled model, Fast-compile may be optionally enabled to speeds up the model's compilation to VPU device specific format. This in-turn speeds up model initialization time. However, enabling this option may slowdown inference due to some of the optimizations not being fully applied, so caution is to be exercised while enabling this option.

Other configuration settings

Onnxruntime Graph Optimization level

OpenVINO backend performs both hardware dependent as well as independent optimizations to the graph to infer it with on the target hardware with best possible performance. In most of the cases it has been observed that passing in the graph from the input model as is would lead to best possible optimizations by OpenVINO. For this reason, it is advised to turn off high level optimizations performed by ONNX Runtime before handing the graph over to OpenVINO backend. This can be done using Session options as shown below:-

Python API

options = onnxruntime.SessionOptions()
options.graph_optimization_level = onnxruntime.GraphOptimizationLevel.ORT_DISABLE_ALL
sess = onnxruntime.InferenceSession(<path_to_model_file>, options)

C/C++ API

SessionOptions::SetGraphOptimizationLevel(ORT_DISABLE_ALL);

Deprecated: Dynamic device type selection

Note: This API has been deprecated. Please use the Key-Value mechanism mentioned above to set the 'device-type' option. When ONNX Runtime is built with OpenVINO Execution Provider, a target hardware option needs to be provided. This build time option becomes the default target harware the EP schedules inference on. However, this target may be overriden at runtime to schedule inference on a different hardware as shown below.

Note. This dynamic hardware selection is optional. The EP falls back to the build-time default selection if no dynamic hardware option value is specified.

Python API

import onnxruntime
onnxruntime.capi._pybind_state.set_openvino_device("<harware_option>")
# Create session after this

This property persists and gets applied to new sessions until it is explicity unset. To unset, assign a null string ("").

C/C++ API

Append the settings string "device_type|<hardware_option>\n" to the EP settings string. Example shown below for the CPU_FP32 option:

std::string settings_str;
...
settings_str.append("device_type|CPU_FP32\n");
Ort::ThrowOnError(OrtSessionOptionsAppendExecutionProviderEx_OpenVINO(sf, settings_str));

C/C++ API

Append the settings string "device_id|<device_id>\n" to the EP settings string, where <device_id> is the unique identifier of the hardware device.

std::string settings_str;
...
settings_str.append("device_id|<device_id>\n");
Ort::ThrowOnError(OrtSessionOptionsAppendExecutionProviderEx_OpenVINO(sf, settings_str));

ONNX Layers supported using OpenVINO

The table below shows the ONNX layers supported and validated using OpenVINO Execution Provider.The below table also lists the Intel hardware support for each of the layers. CPU refers to Intel^® Atom, Core, and Xeon processors. GPU refers to the Intel Integrated Graphics. VPU refers to USB based Intel^® Movidius^TM VPUs as well as Intel^® Vision accelerator Design with Intel Movidius ^TM MyriadX VPU.

ONNX Layers	CPU	GPU	VPU
Abs	Yes	Yes	No
Acos	Yes	No	No
Acosh	Yes	No	No
Add	Yes	Yes	Yes
ArgMax	Yes	No	No
ArgMin	Yes	No	No
Asin	Yes	Yes	No
Asinh	Yes	Yes	No
Atan	Yes	Yes	No
Atanh	Yes	No	No
AveragePool	Yes	Yes	Yes
BatchNormalization	Yes	Yes	Yes
Cast	Yes	Yes	Yes
Clip	Yes	Yes	Yes
Concat	Yes	Yes	Yes
Constant	Yes	Yes	Yes
ConstantOfShape	Yes	Yes	Yes
Conv	Yes	Yes	Yes
ConvTranspose	Yes	Yes	Yes
Cos	Yes	No	No
Cosh	Yes	No	No
DepthToSpace	Yes	Yes	Yes
Div	Yes	Yes	Yes
Dropout	Yes	Yes	Yes
Elu	Yes	Yes	Yes
Equal	Yes	Yes	Yes
Erf	Yes	Yes	Yes
Exp	Yes	Yes	Yes
Flatten	Yes	Yes	Yes
Floor	Yes	Yes	Yes
Gather	Yes	Yes	Yes
Gemm	Yes	Yes	Yes
GlobalAveragePool	Yes	Yes	Yes
GlobalLpPool	Yes	Yes	No
HardSigmoid	Yes	Yes	No
Identity	Yes	Yes	Yes
InstanceNormalization	Yes	Yes	Yes
LeakyRelu	Yes	Yes	Yes
Less	Yes	Yes	Yes
Log	Yes	Yes	Yes
LRN	Yes	Yes	Yes
MatMul	Yes	Yes	Yes
Max	Yes	Yes	Yes
MaxPool	Yes	Yes	Yes
Mean	Yes	Yes	Yes
Min	Yes	Yes	Yes
Mul	Yes	Yes	Yes
Neg	Yes	Yes	Yes
Not	Yes	Yes	No
OneHot	Yes	Yes	Yes
Pad	Yes	Yes	Yes
Pow	Yes	Yes	Yes
PRelu	Yes	Yes	Yes
Reciprocal	Yes	Yes	Yes
ReduceLogSum	Yes	No	Yes
ReduceMax	Yes	Yes	Yes
ReduceMean	Yes	Yes	Yes
ReduceMin	Yes	Yes	Yes
ReduceProd	Yes	No	No
ReduceSum	Yes	Yes	Yes
ReduceSumSquare	Yes	No	Yes
Relu	Yes	Yes	Yes
Reshape	Yes	Yes	Yes
Resize	Yes	No	No
Selu	Yes	Yes	No
Shape	Yes	Yes	Yes
Sigmoid	Yes	Yes	Yes
Sign	Yes	No	No
SinFloat	No	No	Yes
Sinh	Yes	No	No
Slice	Yes	Yes	Yes
Softmax	Yes	Yes	Yes
Softsign	Yes	No	No
SpaceToDepth	Yes	Yes	Yes
Split	Yes	Yes	Yes
Sqrt	Yes	Yes	Yes
Squeeze	Yes	Yes	Yes
Sub	Yes	Yes	Yes
Sum	Yes	Yes	Yes
Tan	Yes	Yes	No
Tanh	Yes	Yes	Yes
TopK	Yes	Yes	Yes
Transpose	Yes	Yes	Yes
Unsqueeze	Yes	Yes	Yes

Topology Support

Below topologies from ONNX open model zoo are fully supported on OpenVINO Execution Provider and many more are supported through sub-graph partitioning

Image Classification Networks

MODEL NAME	CPU	GPU	VPU	FPGA
bvlc_alexnet	Yes	Yes	Yes	Yes*
bvlc_googlenet	Yes	Yes	Yes	Yes*
bvlc_reference_caffenet	Yes	Yes	Yes	Yes*
bvlc_reference_rcnn_ilsvrc13	Yes	Yes	Yes	Yes*
emotion ferplus	Yes	Yes	Yes	Yes*
densenet121	Yes	Yes	Yes	Yes*
inception_v1	Yes	Yes	Yes	Yes*
inception_v2	Yes	Yes	Yes	Yes*
mobilenetv2	Yes	Yes	Yes	Yes*
resnet18v1	Yes	Yes	Yes	Yes*
resnet34v1	Yes	Yes	Yes	Yes*
resnet101v1	Yes	Yes	Yes	Yes*
resnet152v1	Yes	Yes	Yes	Yes*
resnet18v2	Yes	Yes	Yes	Yes*
resnet34v2	Yes	Yes	Yes	Yes*
resnet101v2	Yes	Yes	Yes	Yes*
resnet152v2	Yes	Yes	Yes	Yes*
resnet50	Yes	Yes	Yes	Yes*
resnet50v2	Yes	Yes	Yes	Yes*
shufflenet	Yes	Yes	Yes	Yes*
squeezenet1.1	Yes	Yes	Yes	Yes*
vgg19	Yes	Yes	Yes	Yes*
vgg16	Yes	Yes	Yes	Yes*
zfnet512	Yes	Yes	Yes	Yes*
arcface	Yes	Yes	Yes	Yes*

Image Recognition Networks

MODEL NAME	CPU	GPU	VPU	FPGA
mnist	Yes	Yes	Yes	Yes*

Object Detection Networks

MODEL NAME	CPU	GPU	VPU	FPGA
tiny_yolov2	Yes	Yes	Yes	Yes*

*FPGA only runs in HETERO mode wherein the layers that are not supported on FPGA fall back to OpenVINO CPU.

CSharp API

To use csharp api for openvino execution provider create a custom nuget package. Follow the instructions here to install prerequisites for nuget creation. Once prerequisites are installed follow the instructions to build openvino and add an extra flag --build_nuget to create nuget packages. Two nuget packages will be created Microsoft.ML.OnnxRuntime.Managed and Microsoft.ML.OnnxRuntime.Openvino.