Is PyTorch using a C++ compiler or not?

Hello Everybody,

I used Keras but started recently with PyTorch 0.4.1 under Windows10 on a laptop without GPU. Everything works fine, but I’m surprised that the TaskManager shows me that all the CPU consumption is by python.exe itself. Keras compiles behind the scenes C++ code, which is then executed for speed.
How does that work for PyTorch?
Surely, all the number crunching can not be done in pure Python ??


The c++ code is compiled as python extensions. So from the task manager point of view, it is python that uses these ressources.
Note that in pytorch, all the compilation is done ahead of time, not at runtime.