Detecting Ethernet Cable Category

This is a short case study with iperf , Windows, macOS, and WSL . The Curious Case Recently, I was testing my downstream network performance on my Windows and Mac machines, both of them connected to the same router. The problem was: I was getting ~700Mbps downlink on Windows, while MacOS saturated at >1Gbps. “If I’m only getting ~700 Mbps, my Ethernet cable must be bad, no?” My first guess was…