Sony Vaio VGN-Z31VN/X review

Sony's Vaio VGN-Z31VN/X is easily the most expensive laptop here, but it has some features that set it apart.

For a start, it has two graphics chips - an integrated Intel GMA 4500M HD chip and an Nvidia GeForce 9300M GS chip. A button above the keyboard switches between the two. Neither is suited to 3D gaming as their single-digit scores in our Call of Duty 4 test show, but the onboard Nvidia chip can handle HD movies.

The benefit of switching between them is extended battery life. With the Nvidia chip enabled, the Vaio lasted just under five and a half hours; with the Intel chip enabled, it lasted an incredible eight hours and 15 minutes.

Unlike the other ultra-portables here, the Vaio excelled in all our Windows benchmarks thanks to its fast 2.66GHz Core 2 Duo P9600 processor and 4GB of RAM, although only around 3.5GB can be used because of the 32-bit version of Windows Vista.

The 13.1in screen has a very high 1,600x900 resolution, but small text is still easily legible. The 16:9 aspect ratio is ideal for watching widescreen movies. It's not quite as bright as the Lenovo X360's screen but is by no means dark. Viewing angles aren't as wide as we'd like.

Like the Samsung X360's keys, the Vaio's keys are spaced out. They're comfortable to type on, but they don't give quite enough feedback and are less responsive than the keys on either the Portege or the ThinkPad. The accurate touchpad is large, but the buttons were too small for our fingers.

The 320GB hard disk is large for an ultra-portable. There's a built-in 3G modem, so you can use the ExpressCard/34 slot and the two USB ports for adding other peripherals. Adobe Acrobat is bundled so you can create PDF documents, although there's no copy of Photoshop Elements as there is with Sony's other Vaios in this Labs.

The Vaio VGN-Z31VN/X is expensive, but it's the best ultra-portable laptop available.