When Sony kicked off its SZ series of ultraportables with the VAIO VGN-SZ170P, the company showed that it was the first to understand how important discrete graphics and an optical drive were to performance-seeking world travelers. Battery life was the only element that stood in the way of an SZ-series laptop overtaking the Lenovo ThinkPad X61 Tablet. The Sony VAIO VGN-SZ791N ($2,499 direct) is the latest refresh. It keeps intact the successful compact design while providing a compelling performance boost with one of Intel's new Penryn processors, a 2.5-GHz Core 2 Duo T9300. In addition to tallying improved performance scores, the SZ791N sustained over 5 hours of battery life, enough to earn it an Editor's Choice in the ultraportable category.

The SZ791N has a svelte, appealing look. The carbon fiber lid is beautifully made: Look at it closely and you can make out the fiber strands and subtle sparkles embedded in the coffee-brown exterior. The 13-inch LED screen is amazingly thin—not to mention bright—but the way the lid flexes raises some concerns about possible damage to the LCD. By contrast, Apple has figured out how to limit the bending in its MacBook Air while maintaining its thinness. The keyboard, unlike the one in the Fujitsu LifeBook P8010, is full-size, but Sony needs to work on the resistance of the keys in order to make them top-notch, like those in the perfectly crafted keyboard of the Lenovo ThinkPad X61.

An optical drive is not an absolute requirement—at least, Apple, which didn't include one in the MacBook Air, would like you to believe that it's optional—but kudos to the SZ791N for integrating one in case you want to drop in a DVD movie during that long flight. In fact, the Acer Ferrari 1100, the Fujitsu LifeBook P8010, and the ASUS U6S all have built-in optical drives. The two USB ports are scant compared with the four on the ASUS U6S, though better than the lone USB port on the MacBook Air. The U6S and the Dell XPS M1330 go as far as integrating an HDMI-out port for those who want to hook up their laptops to a modern big screen. For storage, the SZ791N throws in a voluminous (250GB) hard drive, a huge asset to video and audiophiles. The SZ791N integrates a Sprint EV-DO Rev A cellular modem, so you can get broadband connectivity wherever there's a cell phone signal. Many ultraportables still don't have these modems built-in. Among the others that do are the Lenovo X61, the Panasonic Toughbook W5, the Fujitsu LifeBook T2010, and the Dell XPS M1330.

The SZ791N is the first ultraportable to show up on our bench with an Intel Penryn processor, the 2.5-GHz Core 2 Duo T9300. The processor alone helped propel the SZ791N above the competition, delivering outstanding benchmark test scores. It outperformed the ASUS U6S and its Merom processor by 13 percent on SYSmark 2007 Preview Overall, where its performance was boosted by the 4GB of RAM. (Memory prices are apparently low enough now for vendors to be willing to put in the maximum amount. Acer also maxed out the RAM in its Ferrari 1100.) The SZ791N produced the fastest Adobe Photoshop CS3 scores to date, besting the U6S by 19 percent and the MacBook Air by 41 percent. Heavy-duty tasks such as photo rendering and video encoding will be a lot faster on this ultraportable than on the MacBook Air or the ASUS U6S. In all fairness, the MacBook Air and the Fujitsu P8010 use low-powered processors; this explains why the SZ791N was able to run away with top video-encoding and 3D-rendering (CineBench R10) scores as well.

The SZ791N continues to be one of the few ultraportables that run discrete graphics. The nVidia GeForce 8400M GS chipset lets you run many current 3D gaming titles, although you'll need a much better card to run games like Crysis and World in Conflict. Even so, the SZ791N delivered the best gaming numbers among ultraportables with discrete graphics, which include the ASUS U6S and the Dell M1330. The SZ791N runs two separate graphics systems, an arrangement unique to the SZ series. A physical switch above the keyboard lets you choose between the nVidia chipset and the Intel Graphics Media Accelerator X3100, otherwise known as integrated graphics. (You have to reboot for the change to take effect.) Performance, particularly with games and 3D applications, is better with discrete graphics, but when you want to save on battery life and aren't doing any heavy-duty tasks you can switch to the integrated graphics.

MobileMark 2007 tests tallied 3 hours 49 minutes of battery life with its 63-Wh battery. The previous model, the Sony VAIO VGN-SZ370P, scored only 2:43. The improvement in battery life results from the Penryn processor core's greater energy efficiency. If you select the integrated graphics, battery life gets an additional hour and 17 minutes, for a total of 5 hours 6 minutes, according to MobileMark 2007—though you get a performance hit on 3D content.

Understandably, with all its power, the SZ791N cannot possibly adhere to Energy Star 4.0 requirements. It's not EPEAT-certified either, but Sony is adamant about not using hazardous materials in the production of its laptops, so it is RoHS-compliant. On our own energy usage tests with a Kill A Watt meter, the system recorded 23 watts in idle mode and 1W in sleep mode. Obviously, it's not as energy-efficient as the low-powered processors in the MacBook Air and the Fujitsu P8010, but it consumed less wattage than its standard-voltage counterparts: The ASUS U6S recorded 26 watts in idle mode, the Acer Ferrari 110034 watts.

Since its inception, the Sony SZ series has vied with the Lenovo ThinkPad X61 and its predecessors for the top spot as an all-around ultraportable. With the VAIO VGN-SZ791N, Sony has finally pulled past the X61 by being the first to deliver a system with the new Penryn processor. Intel's latest CPU helped the SZ791N deliver a blend of performance and battery life that tops the competition's. For that, it earns our coveted Editors' Choice.

Check out the Sony VAIO VGN-SZ791N's test scores.

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