iperf allows speed testing for network lines, which might be useful to you in some situations, like when your landlord is deliberately choking access. 👿
On an unrestricted line though, here’s what it looks like.
iperf is pretty easy to handle, but you’ll need to connect to a server that’s prepared for it. You can’t just aim iperf at Google and hope for a line speed measurement. (I know, I tried. 🙄 )
However, there are some public iperf servers out there that you can test your strength against. The one you see in that gif was on a list from the Wikipedia page. There are others there if eltel.net is inconvenient for you.
In-house, I imagine this would have more use, since it does offer some line quality options too.
Perhaps you can find out where that annoying whine comes from, when you transfer files between computers. Just kidding. 😉