Why pytorch 1.10 in python 3.6 is slower than pytoch1.10 in python 3.9

why pytorch 1.10 in python 3.6 is slower than pytoch1.10 in python 3.9?

The left is python3.6 and the right is python3.9, i test on the same machine.

Could you share a minimal and executable code snippet showing such behavior in supported versions? Python 3.6 is not supported anymore and PyTorch 1.10 is quite old, so let me know if you see anything similar in new releases.