UK broadband less than half of advertised speedsBroadband speed gap remains wide, finds Ofcom

02 March 2011

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Ofcom speed test results reveal the gap between promised and actual speeds remains large

Average broadband download speeds are still less than half of advertised headline speeds, a large-scale Ofcom speed test has revealed, but fibre broadband outperforms ADSL.

Across all ISPs and all types of broadband, the average UK broadband speed in November/December 2010 was 6.2Mbps. This is an increase from May 2010, when the average speed was 5.2Mbps. 

But the number of broadband customers on packages with high advertised speeds has also increased since May 2010, with average advertised speeds now reaching 13.8Mbps. Because of this, the gap between advertised and actual speeds has not improved with average broadband download speeds just 45% of average headline speeds.

In response to the findings, Which? broadband expert Ceri Stanaway says: 'Ofcom's latest broadband speed test results are disappointing, though unsurprising - frustratingly, there's still a big gap between most promised speeds and what broadband users can get in reality.'

Find out what affects broadband speed and what you can do to improve performance, plus check how the speed of leading UK ISPs compared in Ofcom's tests, in the free Which? guide on how to increase your broadband speed. 

Fibre vs ADSL broadband download speeds

Ofcom's speed tests revealed big differences in speed performance depending on the broadband technology used. 

ADSL broadband

Full ADSL broadband - delivered over BT's copper wire network - had the biggest gap between advertised and actual download speeds. This is primarily because broadband speeds deteriorate over copper wires, so the longer the wire has to stretch from the broadband exchange to your home, the lower the speed it is possible to achieve. Most UK broadband providers currently use ADSL broadband to deliver their services.

The broadband speed gap increases with higher headline speeds - customers on an ADSL service promising between 20 and 24Mpbs achieved just 29% of headline speeds on average. 

Virgin Media and BT Infinity

Fibre broadband services from Virgin Media and BT Infinity delivered much closer download speeds to what was promised. Virgin Media's cable packages delivered at least 90% of headline speeds on average, across its 10Mbps, 20Mbps and 50Mbps packages. 

And for the first time Ofcom was able to measure BT's new 40Mbps broadband service - BT Infinity. This uses fibre for all but the final part of the broadband delivery, and produced on average 80% of headline download speeds. 

Find out more about fibre broadband packages and prices and what Which? members think of BT and Virgin Media's services in the Which? broadband review.

Ofcom's research involved more than 18 million separate service performance tests in over 1,700 homes during November and December 2010.

Theoretical speed advertising misleads consumers

Ceri Stanaway adds: 'It's good to see that fibre broadband from Virgin Media and BT is capable of delivering closer to the headline speeds, but fibre broadband is only available to limited parts of the UK, and the more widely available ADSL broadband still falls far short of expectations.

'We accept that some of the factors that limit broadband speeds are beyond ISPs' control - such as the deterioration of broadband signal over copper wires. But people tell us they find current broadband speed advertising misleading and confusing. 

'It's not rocket science - broadband ads should reflect what the technology can actually deliver.'

The ASA is currently consulting on the way broadband speed is advertised. Which? has submitted a response calling for greater clarity, so that prospective broadband customers can make an informed choice based on realistic speed advertising. 

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