Broadband download speeds in the UK dramatically fall at peak times, according to new research by online comparison site uSwitch.
The outfit said that between 7pm and 9pm, download speeds drop off by an average of 35 per cent when most people are accessing the internet from home.
It based the company's findings on more than two million speed tests carried out via its website between March and October this year. It collected data from speeds measured on ADSL and cable connections.
uSwitch said it had only included postcode areas where over 100 morning and nighttime speed tests had been submitted to its site.
It found that certain parts of the country suffered a much bigger download speed lag than other areas in Blighty.
Weston-Super-Mare in Somerset recorded average download speeds that dropped almost two-thirds (64 per cent) from off-peak morning rates of 9.5Mbit/s to 3.4Mbit/s in the evenings, said uSwitch.
It also highlighted the Cornish town of Wadebridge, which isn't getting so-called "superfast" broadband until the end of 2013. That parish saw a 2Mbit/s drop-off during peak time, with speeds falling from 4.1Mbit/s to a pitiful 2.1Mbit/s.
Evesham in Worcestershire also fared badly in the research. Residents there saw download speeds plummet by 69 per cent from 15.5Mbit/s to 4.9Mbit/s between 7pm and 9pm.
“It really is surprising just how much broadband speeds fluctuate at different times of the day, with drop-offs of almost 70 per cent in some areas of the UK," said uSwitch spokesman Ernest Doku.
"Not many internet users enjoy the maximum headline broadband speeds offered by providers, and certainly not during the working week."
The price comparison site has been criticised in the past by ISPs that complain that uSwitch uses its own "flawed" tech to measure such speeds.
"It is not at all surprising that the actual speeds broadband users experience differ and vary throughout the day as demand for the internet decreases and increases," a BT spokesman told The Register.
"This is especially true during the busiest time, 7pm to 9pm, when global internet speeds are at their slowest simply because of the amount of people using the internet.
"BT Retail invests heavily in bandwidth to ensure its customers get a good online experience during the busy periods. BT offers comprehensive advice about optimising broadband speed and a personalised speed-tester at www.bt.com/help/broadbandspeed."