Speed testing fibre

Hi, I'm hoping you can help.
On switching to Community Full Fibre broadband I have been running speed checks and am puzzled by the results; as there appears to be a major discrepancy between speeds tested by the router suppliers app on my phone and those tested on my PC (both wireless connections).

It is a 500 Mbps full fibre to the home package.
The supplied router is a Linksys Velop
My PC is a Dell XPS 8500 updated with an Intel AC7260 Dual band wireless adaptor - 2.4GHz/5GHz Specced max speeds 300 / 867 Mbps

The Netsys App gives internet speed as 519 down and 535 up measured (I'm guessing) by the router itself.

Meteor App gives 311Mbps down and 148Mbps up measured via my iphone.

Belarc Advisor notes a connection speed of 702 Mbps measured at the AC7260 adaptor.

Think Broadbands speed test gives 234Mbps down and 233Mbps up.

Broadband Speed checker gives 254Mbps down and 204Mbps up.

So, am I correct in thinking that the majority of speed checks are done at 2.4GHz thereby imposing a ceiling on the results or is something else at work?

All bets are off if testing over wifi. Connect a decent up to date device by ethernet to the router directly, what results does this give ?

Wireless speed tests are unreliable as too many factors will affect it. They will be carried out on whichever WIFi link /frequency you have - so conneted om a 5GHz link- it will run over it.

My 5GHx will give me an 866 Mbps connection with a laptop whilst sitting on a swivel chair. Turn through 90 degress and it will drop to 300, or change rooms and 160 maybe.

You need to check using wired and just accept the wirelss as a demonstration you have a good/reasonable/bad WiFi link.

The ideal, even better than from a wired PC is to run it from your router - but not many are capable. Mine does and if I want to check the actual fibre connection, I run it from there.

With wifi, you get what you get.

I have Unifi AC Lite (802.11ac) access points. The theoretical peak speed from this particular model is 867Mbps, like yours. However, doing a speed test to a local server *on my LAN* from an AC laptop connected on 5GHz, within a couple of metres of the AP, I get a little over 400Mbps. And that's after tuning the AP to use wide channels; before that it was significantly less.

With wifi, there are big turnaround overheads when each side has to take it in turns to transmit, so as a rule of thumb, I'd say expect no more than half the claimed peak throughput is achievable in practice, and even that only under ideal conditions.

In your case, you're also testing over the Internet to a remote speed test server, so the figures you get seem well within the expected range.

Your desktop PC is a decade old so may also struggle with a 500Mbps speed test even if you are on a cable.