KEY POINTS:
Internet service provider Orcon has topped a nationwide broadband speed survey.
Broadband performance on more than 12,000 computers was tested, and the results showed that the two biggest providers, Vodafone and Telecom, were not giving customers the best performance.
Two smaller internet service providers (ISPs), Inspire and Snap, also performed, but provide to a significantly smaller customer base.
Orcon's results were significantly better than those of other providers, with an average download speed of 5.2 megabits a second (Mb/s).
Of the major companies in the broadband market, TelstraClear was next with 3.5Mb/s, followed by Vodafone and Telecom. The national average line speed was 3.4Mb/s.
Orcon outstripped its competitors in Auckland, recording 6.1Mb/s as a result of its high-speed ADSL2+ service.
The average performance of all providers in Greater Auckland was 3.8Mb/s.
TelstraClear's solid infrastructure in Wellington enabled it to beat its competition there with a 4.2Mb/s download speed, the capital's fastest.
The survey, conducted by broadband benchmarker Epitiro Technologies and nzherald.co.nz, used a software "agent" on respondents' PCs to get a picture of high-speed internet performance throughout the country.
The results reflect not only the service provided by ISPs, but also the performance of each customer's equipment. Factors such as the quality of internet filters and other devices can affect broadband performance.
Another set of figures suggested that ISPs were struggling to deliver their advertised data speeds at the upper end of the spectrum.
ISPs that promised low-speed performance, under 2Mb/s, were over-performing - some enough to deliver three times the speed advertised - and services around 4Mb/s generally gave customers what they paid for.
But services advertised as being 8-10Mb/s tended to be half that speed.
Telecommunications Users Association of NZ chairman Ernie Newman was not surprised by the discrepancy.
"It certainly shows there's a big disparity between what people expect and what they've got," Mr Newman said.
He advised broadband users to monitor their connection speeds.
"If you're on a premium plan, make darned sure that you're getting what you pay for, and that you monitor it closely."
A customer satisfaction survey run in conjunction with the broadband test showed broadband customers weren't taking broken promises of high-speed internet lying down.
The study showed that customers can tell when they're not getting what they pay for.
"There is a very strong correlation between quality of service and customer satisfaction," said Epitiro managing director Michael Cranna.
"This suggests customers generally know when they are getting a bad deal."
Orcon and TelstraClear outstripped Telecom and Vodafone for customer satisfaction.