All on same Dell Optiplex desktop PC with great care taken to ensure nothing else was using the bandwidth.

are you using the pre install web browser..

if you are - uninstall and re-install

Thanks. I have done this for both Edge and Chrome but both give similar figures. The Speedtest app and the CLI version of Speedtest seem to give higher and at first look a better guide to the actaul speed you are getting in pure terms.

what anti virus are you using ?

ESET. I tried with the real time protection paused but did not see any obvious difference.

ok, try, shut down eset completely by quitting the program. then try chrome in safe mode

Open Run box by pressing Windows+ R keys together on your keyboard. · In the text box, type in: chrome.exe -incognito · Press Enter or click OK.

then go to the same speed test.

That definitely gives higher readings. I then re-enabled Eset and still got similar readings with both Chrome and Edge in incognito modes than in standard browser format. All very interesting. I have learned quite a lot today!

you may have a browser extension enabled which could be part of an issue ..

As its a dell, it may have unwanted apps which is causing some of the issue. As you done the cli/shell test and reported that its ok i'm reluctant to suggest running windows with limited start up programs.

Is the slower anticipated speed affecting your use of the internet?

If doing via browser disable a/v web injection, and tbb and/or fast.com I would use for basic testing.

Both are able to do single threaded tests (tbb does it automatically as well as multi threaded). fast.com is netflix network.