I took a look at Firefox's developer tools network tab while the speed test was running, and I noticed all the requests were being done over HTTP 1.1, even though I had HTTP 3 and HTTP 2 enabled.
When disabling both HTTP 3 and HTTP 2 in Firefox so it only uses HTTP 1.1, most of my issues browsing and downloading from other CloudFlare-hosted sites disappear. For me, transfers suffer most when transferred over HTTP 3, which is enabled by default. HTTP 2 is less affected and HTTP 1.1 feels fine.
I copied this from AKVorrat/Netzbremse.de#12, but I can see https://speed.cloudflare.com behave identically, with all __down requests (and other requests to speed.cloudflare.com) only using HTTP/1.1.
The speed test regularly (but not always) saturates my connection (Deutsche Telekom, AS3320), only rarely dipping into the low Mbps, while CloudFlare-fronted sites using HTTP/3 or HTTP/2 often crawl at sub-megabit speeds.
I took a look at Firefox's developer tools network tab while the speed test was running, and I noticed all the requests were being done over HTTP 1.1, even though I had HTTP 3 and HTTP 2 enabled.
When disabling both HTTP 3 and HTTP 2 in Firefox so it only uses HTTP 1.1, most of my issues browsing and downloading from other CloudFlare-hosted sites disappear. For me, transfers suffer most when transferred over HTTP 3, which is enabled by default. HTTP 2 is less affected and HTTP 1.1 feels fine.
I copied this from AKVorrat/Netzbremse.de#12, but I can see https://speed.cloudflare.com behave identically, with all
__downrequests (and other requests tospeed.cloudflare.com) only using HTTP/1.1.The speed test regularly (but not always) saturates my connection (Deutsche Telekom, AS3320), only rarely dipping into the low Mbps, while CloudFlare-fronted sites using HTTP/3 or HTTP/2 often crawl at sub-megabit speeds.