It depends on how exactly each is tuned. Cache and buffer sizes, drivers, TCP congestion control algorithms, and more can affect this hugely, and are different

It depends on how exactly each is tuned. Cache and buffer sizes, drivers, TCP congestion control algorithms, and more can affect this hugely, and are different. The defaults on linux (and probably on freebsd) also change reasonably often, so you can expect linux 4.x to have singificant differences from 5.x.