Back when 2Mbit connections were the most a residential customer could aspire to, the broadband speed tests that were available were, in general, reliable. Of course, if the server that the test data was held on was over in America, then you could expect slight variance between reported speeds and your actual potential maximum throughput, and if the test data size was too small, you would need to shop around for larger data test schemes. However, as ADSL+ and then ADSL2 became available, some of the older tests, or less reliable servers meant that such tests could not be relied upon to give accurate results. Of course, you could find three or four different suppliers of tests, run each four times and then average the results, but most people don’t bother. Virgin Media has been complaining that those of their customers who complain about slow speeds were often led to false, or at least slightly inaccurate conclusions. So they are apparently teaming up with on such bandwidth test supplier to try and ensure future tests are more reliable. For now, with my 256Kbit/sec connection, I don’t think I need to worry about changing my bookmarked tests just yet 🙂