How did you install PyTorch and NumPy? Are you using conda? I also observe that NumPy is faster on one of my machines (actually, my laptop where I use conda) whereas it isn’t when I compiled it from source (on my work station). I think it has sth to do with MKL and the intel-specific optimizations conda (and/or intel) does for the conda NumPy package:
https://docs.anaconda.com/mkl-optimizations/ 5