FWIW the speed checker on
Broadband.co.uk Dedicated to finding the best broadband for you is probably as accurate as it gets. I know the person who wrote it, and it includes all sorts of edge-case heuristics to make up for lack of decent data from BT.
Just out of interest, is the result it returns the peak speed, or the speed at the end of the test?
The reason I'm asking stems from the following set of tests:
Last night, the only test on that site that actually completed (as opposed to hanging up with the download only 20% complete and the speed dial showing 8kb/s), returned a result of 0.2Mb/s download, 0.41Mb/s upload. The download part of the test took five minutes to complete, with numerous longueurs whilst the bit rate lurked at sub-dialup speeds.
By way of contrast, I ran three tests this morning, and each time the download was complete in a few seconds, returning a mean average of 0.31Mb/s download, 0.41Mb/s upload (which is still pretty poor).
I was running disk cleanup between each test this morning, and what was being cleared from the temporary internet files folder was around 0.5MB.
Assuming that the test file being downloaded last night was the same size, I can safely discount the test result being average speed, because if that was the case, the download should have taken only 20 seconds or so!