Multi-monitor displays are a familiar sight on trading floors and in design studios, but they could soon become a more common sight on the desks of ordinary users, thanks to technology that cuts the cost of supporting a second screen. It also makes adding one as easy as plugging in a USB mouse.

DisplayLink has developed technology that enables an extra display to be added to any PC using a USB connection. Support for this technology is now embedded in some flat-screen monitors from vendors such as Samsung and LG, while Toshiba has used it in a laptop docking station, and plug-in adapters are available that add a USB connection to standard monitors.

Jason Slaughter, marketing director at DisplayLink, said despite the productivity benefits of multi-monitor displays, cost has held them back from mainstream use.

“A typical Intel-based PC with embedded graphics needs an extra card to support more than one monitor, and this can cost half a day in downtime if it has to go back to the IT department to be upgraded,” Slaughter said.

By contrast, a monitor with DisplayLink support can simply be plugged in. “If the DisplayLink driver has been rolled out beforehand, someone can simply go round with the extra displays,” he added.

DisplayLink’s solution is a chip that can be embedded in a monitor, plus driver software that creates a virtual graphics adapter for each monitor connected to a PC. Up to six extra screens can be daisy-chained through the USB port.

While USB displays may not be suitable for the most demanding applications, the technology currently supports resolutions up to 1,600 x 1,200 pixels and can even handle moving video, as the driver only updates each monitor when its display changes.

“DisplayLink uses little CPU time. You can play two DVD movies at the same time, depending on the power of your CPU,” said Slaughter.

Supporting DisplayLink adds about £40 to the price of a monitor, but the company expects this to eventually drop to £10. Slaughter said he hoped display vendors will offer it as a standard feature in business-oriented models.

DisplayLink is looking to support higher resolutions with USB 3.0, which will offer data rates up to 5.2Gbit/s. The firm is also planning for wireless USB later in 2008.

Wireless USB uses a low-power radio link to offer USB 2.0 speeds of up to 480Mbit/s over a distance of a couple of metres. It will enable laptop users to connect up a desktop screen and keyboard without needing cables, said Slaughter.