I thought I would share this in case it helped anyone else.
I recently upgraded my line from 2MB to 8MB and was sorely disappointed at the result. The download speeds were all over the place – dropping well below my original 2MB and never going above 8MB.
Pipex said that the first 10 days after a change their system is testing the line so to wait, which I did. After 10 days it was still no better.
So I went hunting on the Web and came up with the following site: Broadband Reports (tweak FAQs)
And in particular this: Tweak Tester
Turns out my RWIN setting was not optimal – the site checks several settings and suggests fixes and includes the tools to make the changes. It also debunks a lot of nonsense suggestions you find all over the place.
The above helped but it only stabilized my downloads to around the 4MB point – still well short of my 8MB.
I then checked for updated drivers for my Pipex supplied Thomson
SpeedTouch 330 USB modem. This is where I got a surprise. It turns out that the modem operates in two modes – the first is for up to 4MB and will never permit download speeds higher than 4MB. The second boosts it to the full 8MB.
I downloaded new drivers (there is also a registry tweak if you have the correct drivers but they are set up wrong).
This is the link to the support site for the modem: Speedtouch Drivers
What was really weird was that this site had abysmal download speeds – 56k modem level. Odd.
Anyway I am now happily downloading consistently at full speed.