Do single threaded tests give a more accurate picture?

Today's test is pretty much what I get every day and I wonder whether the single threaded result is actually a truer indicator of how good my connection is. There was a time when the single threaded test and multi threaded were very close to one another.

What made me wonder is that the updated SpedofMe test is single threaded only and claimed to be a more meaningful metric.

Both single and x6 are valid indicators of line performance. More significant is when they diverge significantly as in your case. That indicates congestion. Try running the test at different times of the day; I predict you'll find that at quiet times when internet usage is lower the difference is minimal.

Report it as a fault to Plusnet.

Don�t forget speedtest.net also includes a single thread option on all of its servers - I find the Xilo & Vodafone London servers the most reliable/realistic. If your speedtest.net single thread results are ok then there�s probably an issue somewhere between your ISP and TBB servers somewhere, nothing to be concerned about.

His speedtest shows he is on Plusnet. If there was an issue between them and TBB I think we'd have seen more reports.

If the OP doesn't see any slowdowns on the single thread tests on multiple speedtest.net servers and he's not experiencing any slow downs in general use then there's absolutely nothing wrong with his connection. My 330 Mbps FTTP line never sees more than 150 Mbps on the TBB single thread tester yet clocks up ~ 310 Mbps on nearly every speedtest.net single thread server. Do I have sleepless nights over this? Absolutely not

Blowed if I can gind the option for single threaded test on speedtest.net but to Xilo server on there I'm getting 42.3 Mbps. I'm certainly not losing sleep over it, just curious. Today's test is much the same as always.

Click on the bottom to select single thread (default is multi thread):

https://postimg.cc/9rgPxcJL

Duhhh... - I have got no idea why I didn't see that 8^)

15.5 Mbps which is in line with my other tests.

Assuming you are doing this speed test via ethernet cable to your router and not on wifi.
Also assuming you don't have any other of your connected device doing any downloading at the same time.

I have had this issue twice before and on both occasions it was a line card issue on the isp's network infrastructure. On their switch/router rack, on the node I and some other users were connected to.

Once with Vodafone FTTC back in January 2019. This was eventually fixed when they upgraded the line cards around March April time.

The time before that was around 3 years ago on Virgin Media Cable broadband. Again then, they found what they said was a faulty Line card. When replaced the issue was resolved.

P.S. I forgot to add - Also assuming it's like that 24/7.

Edited by mrmarktigger (Tue 01-Oct-19 21:07:49)