Average UK broadband speeds have risen in the last year but at a rate that has still left many consumers struggling to keep up, the latest research by telecoms regulator Ofcom has shown.

In the year to November 2011, average download throughputs rose from 6.2Mit/s to 6.8Mbit/s, which sounds like a healthy 10 percent increase rate until the wide disparities in performance are taken into account.

Superfast broadband is now available to around half the UK population, with consumers able to get between 17Mbit/s and nearly 50Mbit/s on some of these services, comparable to the best urban broadband connections anywhere in the world.

The problem is that more than 75 percent of UK connections remains stuck on copper ADSL rather than fibre, which makes the speeds they can deliver dependant on fixed influences such as the quality of the line and the distance a residence is from the local exchange.

Not coincidentally, Ofcom found that advertised speeds for copper-based services were still falling well short of the claims being made for them, with the average users on 20Mbit/s and 24Mbit’s connections receiving around 6.6Mbit/s; for 37 percent this dropped to 4Mbit/s or less.

 “The research is still telling us that some consumers are not receiving anywhere near the speeds that are being advertised by some ISPs,” said Ofcom chief executive, Ed Richards.

The research found some differences in performance between ISPs at the same advertised speed, but the variation would probably have only a modest effect in everyday use (see Ofcom table below).

Ofcom also referred to Upload speeds as an important issue, a point worth reinforcing because this figure can have a big effect on the overall performance of a connection at certain times. A small upload bandwidth will tie up the whole connection when files are being uploaded, even if the download speed is high.  

A larger issue of speed is whether the increases recorded are good enough to keep pace with the evolution of the Internet itself in terms of streaming, applications and the demands even of basic web pages.

Performance table courtesy of Ofcom.