Most important & as a preliminary request - you need to set “performance fine-tuning” on both Windows & Linux OS, that includes registry, RSS, hw & fw tunings, to make sure the adapters use efficiently the CPU numa/cores
Guidance on this can be found in the relevant User-Manuals
Iperf" is more of Linux oriented test tool, while in Windows it is “NTttcp” test tool that is the equivalent Windows oriented test tool…
I know they have “Ntttcp” fo Linux as well so I would suggest using NTttcp test-toll between the two platforms
and finally - since you use a mixture of inbox-driver (& not mlnx_ofed) in Linux, w/WinoF-2 driver in Windows - chances are that you won’t get optimum performance