Why vastly different speed tests on different sites?

stoofa · 19 Dec 2015 at 02:06

I did post this question into another thread - it's possible nobody knew, also possible it was missed, so I'll post here.

I'm wanting to make sure that my line is working as should be and that I'm getting the kind of speeds to be expected. It all feels quick, but like to be sure.
If I run a speed test at http://speedtest.btwholesale.com/ I get, roughly:
75.1mb/17.1mb
I can do a test at http://www.broadband.co.uk/broadband-speed-test/ and get more or less the same, actually a tad faster.
I can run the test 2, 3 times and get the same result, consistently.

If however I pop over to testmy.net for example my results are poor, and consistently so - 11mb/16mb & 10mb/17mb. Upload more or less as expected, download nowhere hear.
If I pop over to speedtest.net I get the same again - download results on somewhere between 9mb & 12mb.
Obviously these are very much below the expected rates on my "up to 80mb" connection.
But the two sites listed at the top are giving much faster results.

Can anyone think why this might be the case? I'm happy to accept the BT Wholesale and the other site are correct, but right now I'm at 2 sites showing good, as expected results and 2 showing very poor results - so still none-the-wiser.

Cheers.

Akagi · 19 Dec 2015 at 02:09

It depends what servers the sites use. If you use speedtest.net and pick a few servers manually, you will see differences between them. Most sites try to pick the fastest server, whether or not they all arrive at the same conclusion is another matter.

Edit, I was about to post a load of screenshots showing different results of my own broadband speed site to site, but they all appear to be the same today haha.

joeyjojo · 19 Dec 2015 at 09:41

Because often the site at the other end is the limiting factor. If it can only send you 50 Mbps then you're not going to saturate your 75 Mbps connection. Testing outside of busy times is the best way to get good results.

stoofa · 19 Dec 2015 at 12:18

Cheers.
As I've got a couple of sites that definitely seem to be confirming a faster connection I'm not too worried.
I know, from large downloads etc that I'm not on an 8mb connection (as per some of the results).
I'll give it a try over time and see what happens.

Ta

Moley · 19 Dec 2015 at 12:24

On speedtest.net I usually use the Brentford server and get the full 160MB my line is capable of.

Avalon · 19 Dec 2015 at 14:28

It depends on your routing to the server and that servers ability to send data quickly enough, this is how the internet works. Just because you get a good result from one site/server doesn't say you will from every server.

stoofa · 19 Dec 2015 at 16:50

Oh I understand all that - I really do.
If I were getting, for example, a range of results from 55mb - 75mb then I'd accept that as a range, dependant on routing, on traffic etc.
But, when I am constantly getting 71-75 from two sites but I am also constantly getting 8-12 from another that worries me more.
It's a massive difference, not one due to tolerance etc.
It is almost as if some sites do their testing a different way to others and for whatever reason my PC is only responding well to one method.

Avalon · 19 Dec 2015 at 19:41

So because one lesser used indicator is responding poorly you assume you have a problem when the two other well respected sources show you don't? Why not just try downloading some real life content and see if you can max your connection.

stoofa · 19 Dec 2015 at 19:44

Avalon said:
So because one lesser used indicator is responding poorly you assume you have a problem when the two other well respected sources show you don't? Why not just try downloading some real life content and see if you can max your connection.

I didn't realise speedtest.net was a lesser used indicator? Everyone in the "post your speed" thread was using it.
Now, if you're telling me it's a lesser used one and thus lesser respected one, then I'm happy to ignore the results it is giving me.

Avalon · 20 Dec 2015 at 16:26

I can get significantly different results via Speedtest.net, all I have to do is change the test server used. It calculates the optimum server to use based on ping, that's not always the server you'll get the best results from, but they will varie.

OK here are my results over the last few minutes on different servers each time:
15.41/9.37 20ms
10.3/8.14 23ms
19.46/8.47 25ms
17.62/9.36 32ms
13.76/8.86 23ms
25.12/9.39 25ms

The only difference in each test (done from my phone) were the server used - Preston is the fastest for me, I'm in Newcastle which is the first server I tested. The range is huge though, 10.3 to 25.12 is massive. Using the Broadband.co.uk link I get 32.64, if I use something else I will get another figure.