UK communications watchdog Ofcom published the results of its research into fixed line broadband speeds in the UK on Tuesday, and they make for disappointing reading.

Carphone Warehouse-owned brands AOL and Tiscali, as well as incumbent carrier BT are the worst offenders, although all the DSL operators are more or less as bad as each other. Analysts noted that Virgin Media was the only operator to emerge from the survey with any credit, underlining the advantage currently enjoyed by cable over copper.

The research involved over 60 million separate service performance tests in over 1600 UK homes between November 2008 and April 2009.

Ofcom found that the majority of consumers in the survey were happy with the speeds they received although over a quarter of consumers (26 per cent) said that the speed they received was not what they expected when they signed up to the service.

During April 2009, the latest month for which data was gathered, Ofcom’s research revealed that the average broadband speed in the UK was 4.1Mbps, compared to an average ‘up to’ headline speed of 7.1Mbps.

Actual speeds received varied widely. Fewer than one in ten (nine per cent) of 8Mbps subscribers received actual average speeds of over 6Mbps and around one in five (19 per cent) received on average, less than 2Mbps.

Consumers on all ISPs experienced a slowdown in actual speeds during peak evening hours (8-10pm), with speeds in this period around 20 per cent slower than over a 24 hour period.

In fact, the survey also pointed out that no one using DSL gets the 8Mbps commonly advertised, and Ofcom suggested that it is impossible for anyone to ever get this speed over DSL, due to signal attenuation inherent in copper, unless they live “very close” to their local exchange.

Investment firm Execution Ltd. noted that Virgin Media does much better than its rivals, with an average speed of 8.1-8.7Mbps, which the analyst described as rather impressive compared to its “up to 10Mbps” claim.

Execution said these negative results matter for BT and Carphone Warehouse, which will nit-pick over the survey methodology, and the fact that Virgin only covers around 50 per cent of homes in mostly urban areas. “But perception is everything, and 26 per cent of customers say they are not getting the speeds they expected when they signed up, with 20 per cent dissatisfied with the speed they are actually receiving. This will surely drive churn towards Virgin Media, especially now customers have evidence that Virgin is able to deliver faster speeds more reliably.”

Ofcom has released a consumer advice video on practical tips to improve broadband speeds in the home