As pointed out speedtest results can be inaccurate and in some cases wildly so, for a number of reasons - just look at the VM speedtest page vs normal speedtest vs the desktop app, above a certain point the web based clients are less accurate. One thing that isn’t variabke is the date in VM’s press release, 20th of November, other than closed trials (and believe me, you’d know if you were on one) they weren’t secretly piping you with an extra 150Mbit over provision on a 500Mbit service before that.
Why are you being so obtuse? I'm not new to this as I had worked for quite a few years as an I.T engineer so when I say they were giving me 150Mbit over 500Mb/s that's exactly what was happening. Why? I have no idea and didn't really care, I didn't even contact them just in case it changed and just enjoyed the extra speed.
Actually they were giving me more than 150Mbit because I can see what my actual sustained and average speed is using DUMeter, which I have had running on my computers desktop probably for over 20 years!
https://www.hageltech.com/dumeter/about
Speedtest actually under valued my real speeds which where usually ~679 Mb/s. Which is what was my sustained maximum speed.
This has been pretty much my modem status page since last April.
There you can see my that my Max Traffic Rate is 690000278, which explains why I was getting ~679 Mb/s and also shows you were also simply wrong when you categorically said that you can not get 650 Mbit on M600 or M500 for that matter.
Nope nothing like that. I disconnected every single device and just left the ethernet in on each of my PC's. No difference
Like I said above, the pattern is the same every day. From about midnight to 5pm I get full speed. After 5pm until midnight it's all over the place
You're suffering from congestion, which I had many years ago on VirginMedia. Actually now, my speeds have dropped off over the past week and I'm only getting around 400 M/bs sustained speeds so the network in my area is also bogged down.