We have performed large file transfers over HTTP from the Hetzner - CX21 cloud server, both downloads and uploads and we measured their speed.
The transfers involve multiple files, 10 threads and they last for at least 10 seconds at maximum speed. The transfers are repeated 4 times from different servers and only the fastest is used for comparisons and to calculate the grades.
You may experience faster speeds using you own Speedtest client. This is because VPSBenchmarks deliberately excludes Speedtest servers with a ping latency under 6ms from the VPS in order to avoid measuring intra-datacenter transfer speeds, which are not representative of the real world.