This is real. I have had it confirmed to me by a Comcast employee. And really, this shouldn't surprise anyone.
Ask HN: Internet magically gets faster when opening speedtest?
11–20 of 356 posts
Re: Ask HN: Internet magically gets faster when opening speedtest?
#12Not very scientific but you can try something that is unlikely to be whitelisted.
Eg. http://134.209.196.181:8080 This is an instance of https://github.com/e7d/speedtest running on Digital Ocean in Amsterdam.
Re: Ask HN: Internet magically gets faster when opening speedtest?
#13Impossible to know for sure, but the ROI on “accelerate packets that match an IP whitelist that is drawn nightly from the DNS records for well-traveled speed test sites” must be quite high.
Could speed test sites do something about this? Like obfuscate the traffic somehow to get more genuine results?
It's possible to build a speed test site out of media file fetches from otherwise public assets from third party sites, the quality of the measurement will just be a little noisier. In many ways this would actually be a better test than some well-placed IP address, since there is a chance to randomly sample many different routes from the ISP to real world destinations for practical object sizes (i.e., not just an idealized unidirectional stream with no request roundtrips in between).
For example you could do something with Image.onload event, but even better are the recent JS web performance APIs, they provide a huge amount of detail - including DNS lookup latency, TCP connect time, TTFB etc.
Actually now I want to build this
edit: I'm probably not going to build this, but you should. For large object sources, there are Flickr full size images, HLS URLs for video on demand systems (each HLS segment is generally around 1-3MB), etc.
I'd want a giant list of these to pick from at random, and probably want to bucket the results along (domain name, destination BGP ASN, destination GeoIP) axes as well as whatever the JS performance API offers. You could maybe present each axis as some kind of confidence interval, then geometric mean to produce an overall score presented graphically somehow
You could then collect up all these scores and publish stats bucketed by Internet provider. And that's the point where I realized I don't have the energy to build all this ;)
Re: Ask HN: Internet magically gets faster when opening speedtest?
#14So the trick is to always be running a speed-test in the background?
A simple Bash loop could suffice, if it's enough to ping the site:
while : do ping speedcheck.org ; sleep 10 ; done
Fast internet forever!
Re: Ask HN: Internet magically gets faster when opening speedtest?
#15Re: Ask HN: Internet magically gets faster when opening speedtest?
#16A twitch art vtuber steamer had a similar realization:
Running certain online games in the background (I think it was final fantasy) fixed problems with the art/drawing/just chatting stream dropping frames.
(Sorry I forget who, I also think it wasn't someone I normally watch so it's unlikely I will remember.)
Re: Ask HN: Internet magically gets faster when opening speedtest?
#17Re: Ask HN: Internet magically gets faster when opening speedtest?
#18I wonder if one could route all traffic through a speedtest site
Re: Ask HN: Internet magically gets faster when opening speedtest?
#19I was cursing on my ISP for a long time till I understood that Im on a 100Mbit wifi.
Then added a wire connection to my server and instantly 10x the speed :^]
Dont be like me, have wires set up everywhere where needed.
Re: Ask HN: Internet magically gets faster when opening speedtest?
#20I was on the phone with a buddy trying to troubleshoot Local file transfer speeds vs Speedtest results.
Speedtest kept reporting 100Mb/s range speeds (the tier he was paying for). Local file transfers however were stuck in the 1MB/s range.
After some questions and troubleshooting he discovered that he had used a 10Mb/s hub instead of a 1Gb/s switch that was sitting right next to it. A simple mixup.
His internet connection was also plugged into that same 10Mb/s hub.
There is NO WAY his PC could have reported 100Mb/s to speedtest.
Do not trust them for accurate results.