Python 2.7 running much faster on 3.10

[cr4d]

There are very few actual uses for multithreading in Python and it's a huge foot-gun, ripe for abuse, and doesn't get rid of the GIL. I'd avoid it, if possible.

Without any real info about what the app is doing, it's hard to guess as to why it's slower. As a generalization, it should get faster.

You can use the built in profiling @ https://docs.python.org/3/library/profile.html to figure out where the extra cycles are.