Run this in Scratch 3.0: https://llk.github.io/scratch-gui/develop/#185127642 It won't do anything very interesting in Scratch 2.0! You should clear your cache before you run this. (Note - your cache, not your history, which is unrelated but often managed from the same dialog.)
Scratch 3.0 instruments are downloaded on-demand, so you can measure how long it takes to download the file and compare that with an expected file size (hard-coded), which gets you your download speed. In this case it's measuring the connection to the domain "https://gleitz.github.io", which is of course owned by GitHub. Here's the place we're grabbing files from: https://gleitz.github.io/midi-js-soundfonts/ - interestingly it's not owned by LLK. I wonder if the ST will eventually host instrument soundfonts on their own servers/domain? At the moment, if Scratch 3.0 went live, gleitz.github.io would probably get a lot of traffic :) (Not that that would be very disruptive; it probably all goes to GitHub's own servers, which obviously expect this sort of strain.)
