CNTK model format

CNTK allows users to save a model into a file for future use. It can be done by

• specifying "modelPath" in the config file when using BrainScript/cntk.exe, or
• save() in python, or
• Save() in C++ when using CNTK Library API.

There are two different file formats to store the model in.

• The model-v1 format. This format was originally used prior to the CNTK2 version. A model is stored in the model-v1 format when it is saved by BrainScript/cntk.exe.

• The model-v2 format. With CNTK2, a Protobuf based format is introduced, which is now known as the model-v2 format. A model is saved in this format only when using CNTK Library API

  • by save() in python, or
  • by Save() in C++.

The following table gives an overview about which model format is created and consumed by which CNTK binary.

	Model Creation	Model Evaluation	Lanugage Support
model-v1 format	cntk.exe	EvalDll, CNTK Library	BrainScript, C++, C#/.NET
model-v2 format	CNTK Library	CNTK Library	C++, C#/.NET, Python