Why PC, mainly laptop, wifi is working and processing so much harder and more heavily when the internet data it receives is at low speed and/or intermittent, as opposed and not due to weak wifi signal strength i.e. its low dB.

What actually is whichever processor(s) is/are working and/or searching on, and what actually has triggered it/them to obligatorily working and processing in such the mentioned conditioned ?
How do we mitigate or solve this (mainly my) problem ?

 

Lots of retry attempts will make the CPU more busy, especially if the wifi adapter is a lower end one with little "smarts" in it. That makes the software driver do more work.