Three Reasons Why You Should Not Use iPerf3 on Windows

Brodde You are, of course, welcome to recommend whatever you prefer. Just as Microsoft is welcome to recommend whatever we prefer.

There are other ways you can test without viewing source code. It's not like Microsoft can quantum teleport packets between Windows and Linux (could you even imagine how much wealthier we'd be if we could?).

Setup a port mirror (SPAN in Cisco terms), switch logging, and/or a sniffer appliance/tool of your choice between two systems of your choice. Run an ntttcp trace between said systems.  Measure the throughput on the wire and see how it measures against reported results. Or use ntttcp on Linux plus whatever trusted tools and metrics in Linux you prefer to measure generic throughput. It would be rather trivial to certify that the results are accurate since the traffic must traverse mediums that Windows and Microsoft does not control. If you do find a reporting error, because errors do happen, please submit an issue on GitHub, let me know, and I will engage people who can address any issues.

But, please, do not make unfounded accusations here.