Just got fiber internet--cheaper and 25x faster uploads than the local cable monopoly's internet: cable upload was 10 Mbps, the fiber's giving me 300 Mbps (although I'm only paying for 100, so hey : ). I clocked uploads in various applications at over 200 Mbps with the fiber hooked up, but my uploads in Firefox were slow, were only going up to about 20 Mbps. Turns out it's due to a bug in Firefox that they've known about for at least two years. : P To fix it I followed the instructions in the reddit comment linked via the "Source" link at the bottom of this post.
Specifically, I did this:
'Set "network.http.http3.enable" to false in about:config and restart the browser.'
And that fixed it. Silly Firefox. ; P
Note: the 20 Mbps upload speed limit in Firefox didn't show up in internet speed tests (Google, Ookla); it DID show up when trying to upload multi-gigabyte videos to YouTube through the browser, though.
