ULV is a fashionable abbreviation in mobile computing right now. It is stands for ‘ultra-low voltage’ and, in essence, it refers to a computer processor that is power efficient, which is great for laptops and other mobile gadgets.

Samsung claims, thanks to the Intel Core 2 Duo SU7300 ULV processor inside it, its new X420 laptop will work for up to nine hours on a single battery charge.

We didn’t quite get nine hours of useful work out of the X420 off mains power but we were impressed with the stints it did put in. Depending on how the machine was used, we squeezed between five and eight-and-a-half hours out of the battery.

Another benefit of ULV processors is that they give out less heat than a standard computer processor, which means laptops can be made slimmer (with less heat to worry about it’s possible to dispense with the large cooling fans found inside most computers).

Indeed, the X420 is pretty slim (31mm, or just over an inch) and, at 1.7kg, not too heavy for a laptop with a 14in widescreen display. It's small size is in part due to the lack of built-in optical drive – an external DVD writer, which can be plugged in when required, is included in the box.

The display, which includes a webcam mounted at the top of the screen area, was wonderfully bright and clear. However, it is so thin it tended to wobble when used on the move.

The Home Premium edition of the Windows 7 operating system is installed, and that Intel SUY7300 processor is supported by 3GB of RAM and a 320GB hard disk.

These components worked sufficiently well together and made Windows 7 run at a very good speed. The X420 can hold a maximum of 4GB of memory, though, and it’s a shame Samsung didn’t go all the way here.

The trackpad supports the multi-touch controls that are part of Windows 7. For instance, a sweep of a single finger will move the mouse pointer across the screen as normal but a two-finger gesture can be used to scroll through documents or web pages.

Pinching with two fingers will zoom in or out of documents. It may sound complicated but it soon becomes second nature.

The X420 has a lovely keyboard, too, with broad key surfaces so there is little danger of accidentally hitting adjacent keys, and plenty of ‘travel’ when the keys are pressed, making it comfortable to use.

The X420 has three USB ports, connections to wired and wireless networks (of all kinds), Bluetooth, a memory card reader and a HDMI socket (for outputting movies to a suitably equipped flat-panel TV, for instance).

Our only qualm was that the built-in speakers are a little weedy. Still, there is an audio output socket so a pair of headphones or speakers can be connected.

With all of the impressive credentials of the X420 we reckon Samsung has a winner on its hands.