All good - realtek aren't that bad at the end of the day, I'm running my internet connection through a 100M ADMtek card from ~2004 :D Well it probably was 10M

All good - realtek aren't that bad at the end of the day, I'm running my internet connection through a 100M ADMtek card from ~2004 :D Well it probably was 10M then. The port LED on the switch might've changed color as well. (Smart reminds me of the consumer-lite answer to SDN.) I just tried fast.com myself using 100kbps and it quite happily measured at line rate (6.8M+800k, yay D:). For some bizarre reason I found I needed to open a new tab, open the devtools, set the network speed, then load fast.com for it to work. My guess is that Chrome applies connection ratelimiting metadata as new connections are created, such that existing sockets still in keepalive aren't affected. I'd say that's at least a documentation bug. I'm not really able/sure how to reproduce the other comment I linked (using an actual 10M switch and seeing 100M of throughput). That's really interesting.