Int8 Calibration Implementation( PTQ) using Int8EntropyCalibrator2 needs DLA mendatory

Dear Team,

Below is my environment details.

Model Type :: Onnx( Translated form Pytorch)
Docker Image of TensorRT, Linux OS
TensorRT Version : v8.2.0.6
GPU Type : Quadro P2000
Nvidia Driver Version : 510.73.05
CUDA Version : 11.4
Operating System + Version : OS 18.04

I am working with TensorRT Docker on Ubuntu OS.
I am trying to implement the calibrator in the C++ API based application.

GPU on my PC doesn’t have DLA , so I am facing Segmentation fault with the API call below:

custom_calibrator.reset(new Int8EntropyCalibrator2<BatchStream>(calibrationStream, 0, "SFA3D_Onnx", mParams.inputTensorNames[0].c_str()));

Can you please confirm if we need DLA supported GPU only to test the calibrator in the application?

Thanks and Regards,
Vyom Mishra

Please check the below links, as they might answer your concerns.


Hello @vyom.mishra ,

Try using IInt8EntropyCalibrator instead of Int8EntropyCalibrator2. For Int8EntropyCalibrator2 it is required for DLA but not sure if it works only on DLA. see here.

Thanks !! 😊

BTW I need help here if you have any idea it will be great. I am basicaly doing something similar to you in C++ please have a look.

Best regard,


Please refer to the API doc.

Thank you.

Dear Harry-S,

I am working on Docker setup on my Laptop which has a Quadro P2000 GPU( no DLA present).

As both IInt8EntropyCalibrator and Int8EntropyCalibrator2 is inherited from same class and has the same member function call, it is giving segmentation fault at API itself. Even class for IInt8EntropyCalibrator is missing from the header file. So , I created the similar class as of Int8EntropyCalibrator2 but din’t suceed.

If you are running your implemented calibrator on Docker , let me know.

Thanks and Regards,
Vyom Mishra

hello @vyom.mishra ,

I am new to these stuff but I think that the calibrator classes are defined in NvInfer.h here if I am not mistaken. I am working on Jetson AGX Orin and I would like to run an ONNX model and do quantization with INT8 calibration using API C++ but I don’t know how do do it, it is my first time that I toutch TensorRT. I am still surfing on Internet. If you figured out how to do it and you like to help me it will be great 😊 and I will help you of course if I could obviously 😁.

Best regards,

Hello @spolisetty @vyom.mishra,

I am facing “segmentation fault” when I set the INT8 precision and not with the calibrator (look below)


// OR one of these below command:

// samplesCommon::enableDLA(config, 1);
// samplesCommon::enableDLA(builder, gUseDLACore);
// samplesCommon::enableDLA(builder, config, gUseDLACore);
// samplesCommon::enableDLA(builder->get(), config->get(), gUseDLACore);

I don’t know why and I don’t know which one is correct and which one we must use.


I would like to know if you have any idea on how we can see which TensorRT version C++ API we are using. like for example in python is very simple :


So how we can print out the current version of TensorRT that we are using in C++.

Thank you

Best regard,

Hi Harry,

Please create a new post with the issue repro script/model.
Which platform are you using? If you’re using the Jetson platform,
we recommend you to please create a post in Jetson related forum to get better help.

Thank you.

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