Environments such as stock exchanges like to have a lot of monitors, but having half a dozen graphics cards isn't often practical.

UK-based Display Link has developed technology called Ubisync that lets you link up monitors via USB.

Samsung has the technology exclusively until spring 2008 and its 940UX is the first to use it. You get a regular DVI and VGA port, one USB device port and a two port USB hub, so monitors can be daisy chained.

We found contrast and white levels very good and the screen is bright with good viewing angles. When viewed from below things petered out a bit, but this only a problem if you use the monitor in portrait mode - something that can't be done when using the USB connection.

Ubisync is exceptionally easy to use. Onboard flash memory contains the driver so you just need to plug it in, restart, and you're away. Our test system wouldn't boot with it plugged in, however, as the Bios got confused with the flash drive (parading as an optical drive) being attached.

For office work it's an elegant solution, but as soon as you start playing video or a DVD, the frame rate suffers and colours gradients deteriorate.

On our 2.8GHz Pentium 4 with 1GB of Ram, we noticed a substantial performance hit when playing video. The application Displaylinkservice.exe consumed 35-40 per cent CPU time, which explains the hefty minimum requirements of a 1.2GHz processor and 512MB Ram when using two Ubisync monitors, rising to 1.6GHz dual core processor with 1GB Ram when using six.

The stand is adjustable with swivel, tilt and 8cm vertical travel, although it doesn't travel as high as some monitors.

The monitor can't be used with any kind of 3D hardware acceleration either, ruling out games and there's a price premium associated with Ubisync, but it's a neat way of setting up multiple monitors.

28/01/2008: We've since taken a look at newer drivers available for this monitor. You can read about its performance and added features on our blog.