Lab

Ultraportables

Most laptops rarely travel further than from the sofa to the kitchen table, but ultra-portables are designed for greater things. With weights as low as 1kg and battery lives up to six hours, the models in this month's Labs can travel with you every day. They're stuffed with ways to connect to other devices wirelessly, and some even have a 3G mobile broadband modem, allowing you to browse the web when you're miles from a wireless hotspot.

With prices ranging from £240 to £1,245, we've taken a wide cross-section of models to see what's available at different budgets. So whether you want to catch up on emails on the train, check the weather forecast on a mountain-top or watch Snakes on a Plane in the departure lounge, there's an ultra-portable laptop here for you.

All laptop PCs have some compromises, and an ultra-portable simply skews the balance more in favour of mobility. Luxuries such as massive screens and supercharged 3D games performance are out, and low weight, long battery life and tough chassis are in. However, finding the right balance is a tricky process, not just for laptop designers, but also for customers. There's more than one great model among the nine in this month's Labs, so it's worth bearing a few things in mind when deciding which is right for you.

Trip the Light Fantastic

The average laptop weighs around 3kg, so something has to give to make one that's nearer 1kg. The nine models in this Labs test approach this challenge in a number of different ways. Arguably the simplest is Acer's Aspire 2920. It has a 12.1in screen, but otherwise its design, internal components and price aren't much different to the 17in Acer 7720G in last month's Labs. This makes it the heaviest laptop here, but also the most powerful and, arguably, the best value.

The laptops from Asus and Vye take the opposite approach. At around 1kg, these really are featherweights, but they achieve it by using cramped screens and keyboards, small batteries and low-power components that stop the diminutive chassis getting too hot but also limit performance.

Another common technique is to reduce size and weight by omitting features. Four of these laptops don't have a built-in optical drive, which is reasonable since many people use them only occasionally to install software. However, we appreciate Packard Bell's inclusion of an external USB DVD writer in the box, especially as it's one of the more affordable laptops.

We also appreciate how the Toshiba and Vye laptops have built-in DVD writers and yet are among the lightest models in the group. In doing so, they demonstrate that making a light laptop is also about clever design. The Toshiba is the best example, as it has no notable omissions or downscaled components and yet is very thin and light. However, its one compromise is its thin, plastic chassis, which doesn't feel as sturdy as those of the competition. It's difficult to say whether or not this equates to inferior build quality, though. Most laptops would suffer serious damage if you dropped them, and the internal components would usually fail before a chassis became physically damaged.

Like all the other £1,000-plus laptops here, the Toshiba has a motion sensor that parks the hard disk's head if it detects rough treatment, reducing the chances of the head hitting the disk's platters and causing damage. However, we're sceptical that these systems, which detect excessive forces, are smart enough to brace for impact when they detect no force at all - that is, when they're in freefall. The visual feedback provided by the laptops reviewed here suggests that this technology is only really effective at protecting against repeated shakes rather than a quick trip towards the floor.

Powering forwards

Battery life is just as important as weight in an ultra-portable laptop. This depends on a number of variables, and again, some of these demand compromise in other areas. The size of the battery directly affects how much charge it can hold, but a bigger battery weighs and costs more. The other approach is to use less power-hungry components. Most LCD screens use fluorescent tubes to illuminate them from behind, but ones that use LEDs are more energy efficient.

Processors also vary greatly in their power consumption. Various tricks are employed to increase the efficiency of laptop processors, but ultimately, the most effective technique is to run them at a lower clock speed. Doing so directly reduces energy consumption and also reduces the need for power-guzzling cooling fans. This is why many of the laptops reviewed here don't perform as well as similarly priced desktop-replacement laptops. No ultra-portable laptop we know of has a powerful graphics processor, as the ability to play 3D games is way down on the list of priorities compared with battery life.

Upwardly mobile

Because ultra-portable laptops are often used for work, many of the models here include features specifically designed for business users. Windows Vista Business and XP Professional provide better backup and networking facilities than Vista Home Premium at the expense of features such as Media Center, while fingerprint readers are a secure alternative to password-protection. Many include a 3G modem as standard or as an optional extra for broadband internet access on the move. See the box below for details.

Whether it's for business or pleasure, the laptops in this month's Labs have a huge amount to offer.