Improvements in technology and the desire for increased performance mean that desktops will become obsolete every three years, warned analyst Giga Group.

In the study Desktop technology refresh rates: how to decide when to upgrade, Giga analyst Rob Enderle reported that users will need to replace PC and laptop hardware regularly if they want to keep pace with the performance demands of new software.

The report suggested that the advent of the Intel Pentium chip and the need for greater performance first prompted the growth in PC replacement rates. Recently, memory has had a greater impact on perceived performance than processor speed.

Giga said that companies should also be aware that certain key software vendors only plan to support hardware that is less than two years old with any new operating system product releases.

Users should now go through an upgrade cycle whenever systems reach a point where failure is likely, or drop below 50 per cent of the overall system performance of newly released products. This is typically three years for desktops and two years for mobile systems, said Giga.

Martin Harvie, systems developments executive at Josiah Wedgwood, said: "We replace our desktops every three years, and that's because you need to keep up with Microsoft's standards. You have to jump into the current flavour but only when there's a strong business case."

Giga's report added that refresh rates can vary depending on how companies use equipment and how aggressively they move to new technologies.

The analyst suggested that, as users shift their reliance from desktop to server-based applications, they may be able to justify decreasing the cycle rate.