A study by UK broadband comparison site www.broadband-expert.co.uk has revealed that, on average, broadband customers receive just 48% of the advertised download speed. The study tested 41,230 broadband connections over February and March 2008 comparing the actual speed customers were achieving against the maximum speed quoted for their broadband package.

The research revealed significant differences between providers and packages with services quoting lower maximum speeds much more likely to get close to the advertised speed. The average actual speed achieved in the 16Mb+ category was a relatively low 8.6Mb and just 45% of the quoted maximum speeds. By comparison customers on 2Mb packages achieved on average 1.8Mb or 88% of the quoted maximum speed and customers on 8Mb achieved 3.4Mb or 43%.

The average speeds achieved by broadband users varied hugely between providers and packages. In the 2Mb category top performers were Virgin Media’s cable service, Talk Talk and UK Online, all of which achieved slightly more than the advertised maximum 2Mb speed. Even the lowest performers Tiscali, Pipex and Toucan achieved 68%, 70% and 73% respectively.

The biggest variations were in the 8Mb category where O2 and Be achieved 73% and 68% of advertised speeds, compared to just 26% for Toucan and 29% for both Virgin Media’s ADSL service and Eclipse.

The fastest actual speed achieved in the 16Mb+ category was Virgin Media’s cable service with an average of 10.4Mb or 52% of the 20Mb quoted top speed. The only other ISP to deliver more than 50% of the advertised maximum speed was UK Online which achieved 62% of the 16mb quoted top speed, delivering an average of 9.99mb.

Broadband Expert Technical director, William Harvey commented: “It seems clear that providers are promising speeds far greater than they are capable of delivering with top end packages. If the ISPs (Internet Service Providers) set a realistic expectation of the speeds that can be achieved, they are much less likely to upset consumers than those who advertise fast speeds and under deliver”.

Harvey went on to comment “There are a number of factors that affect broadband speed but when you see such large differences between the top performing ISP’s and the under achievers, it is clear that this is down to much more than the usual excuse of poor line quality or the customers’ distance from their local exchange.”

One reason behind poor speeds is contention ratio which describes the maximum number of people that can share a connection. Significantly, one of the surveys top performers, UK Online, has contention ratios of 33:1 and 20:1 (dependent on the package chosen) compared to the industry standard of 50:1. Harvey added that “broadband providers operating on higher contention ratios are likely to see their connections slow down at peak times when more people are online”.

Full results of the survey can be found at Broadband Speed Test .