Sony's VAIO Z-series offers some of the most complete ultraportable laptops currently available. Its latest model, the VAIO VGN-Z31VN/X, is a powerful machine that also boasts a wealth of impressive features.

The 13.1-inch screen provides vivid colours, aided by LED backlighting. It's also very detailed, thanks to its 1600 x 900-pixel resolution. Sony has also chosen not to include a glossy Super-TFT screen coating and, therefore, you'll find less in the way of irritating reflections.

The laptop features two graphics cards – an integrated Intel chip and a dedicated nVidia GeForce 9300 GS. You can swap between the two at the flick of a switch to manage power and battery life effortlessly.

Sony vaio vgn-z31vn/x
LUDICROUS SPEED: Flick the switch on the Z31 to boost the graphics power

The slim chassis is crafted from brushed aluminium and looks great, although it is not as solid as we'd have liked. The keyboard is one of the best we've seen and uses the isolated style favoured by Sony and Apple over the past year.

Internally, the laptop packs quite a punch. The 2.66GHz Intel Core 2 Duo processor is as powerful as you'll find in this sort of laptop and is coupled with a stunning 4096MB of DDR3 memory, which ensures the laptop runs smoothly and fast.

We tested the laptop with the integrated GPU selected and had no trouble in multi-tasking both office
and resource-intensive multimedia applications, and the battery life lasted an amazing 529 minutes. We then ran the benchmark with the dedicated GPU selected and the machine's performance was even more impressive, although battery life dropped to 384 minutes.

Ample storage

The 320GB hard drive is among the most capacious in this group and enables you to carry around all your work documents and also music, movie and photo libraries. The 1.5kg chassis is light enough not to be an inconvenience, and the superb battery means you can leave the charger at home.

Integrated 3G/HDSPA functionality allows wireless broadband web access, along with 802.11n Wi-Fi for use in wireless hotspots. A Gigabit Ethernet connection is also included and Bluetooth is in place for communicating with peripherals.

There are two USB ports for peripherals, one mini FireWire for data transfer and HDMI and VGA out ports for connecting to high-definition (HD) and analogue external screens and projectors.

The Sony VAIO VGN-Z31VN/X is one of the best laptops we've seen for a while. Combining power, portability and usability completely and effortlessly, we have no qualms in recommending it as the best ultraportable currently available.

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