ESP8266 is much faster than ESP32 with pubsubclient

[sblantipodi]

As title.
With ESP8266@160MHz I can send 90 message per second using pubsubclient,
same code on ESP32@240MHz process only 40 message per second.

ESP32 is supposed to be much faster, what's happening?

This is what the author of the lib says:
"the library is platform independent - that is why you pass in a network client implement into this library. I honestly can't see why any of the pubsubclient code would behave differently on different platforms. What seems more likely to me is the network client which will be more closely tied to the particular hardware it is running on."

Thank you!