Friday, May 9, 2008

The Best Mainstream and Ultraportable Laptops

Making an ultrathin laptop requires a careful selection of components, as well as a willingness to push the limits of technology.

Laptop makers strive to build their ultraportables ever lighter and thinner without skimping on features or power. Last year's Toshiba Portégé R500 and Sony VAIO VGN-TZ150N were trailblazers in the thinness quest. Both fit optical drives in sub-3-pound frames less than an inch thick. (The R500's DVD drive is just 7mm thick.) They both have motherboards the size of your hand, and other miniaturized components. Yet trade-offs were made. The R500 and TX150N have a meager 1GB of RAM apiece (we recommend 2GB to run Vista), and their CPUs are weak.

The latest thinness champ is the Apple MacBook Air. Its thickest part (at the back, lid closed) is 0.76 inch, about the same as the R500's thinnest point, yet the Air tapers to just 0.16 inch at the front bezel. Though it would be swell if every laptop could fit into a manila envelope as the the MacBook Air does, Apple paid a price for pushing the envelope (pun intended) on size, doing without a DVD drive and removable batteries. There's no magic involved—design is a science. We'll look at what went into making the Air and other ultrathin laptops, as well as some of the compromises required.

A compelling aspect of the MacBook Air's design is the layout of its innards. The first thing you see, once you unscrew the base plate, is the (1) huge but ultrathin battery, which fills two-thirds of the laptop. The (2) motherboard and the (3) hard drive take up the rest. Apple squeezed the (4) 802.11n wireless module, about half as big as the PCI Express Mini Card Wi-Fi adapters used in most laptops, into a corner. There was room for only a single (5) USB port, plus a mini-DVI port and headphone jack.

PC makers are using strong yet lightweight materials to create thin frames. The Sony TZ150N used carbon fiber; the Toshiba R500, a sturdy plastic. The MacBook Air employs aluminum alloy.

All the ultraportables featured in this story, except for the Acer Ferrari 1100, use LED-backlit screens, which are replacing CCFL (fluorescent) tubes. LED screens are a bit thinner (and can be held by thinner frames) and more energy-efficient. One reason LED screens are thinner is that LEDs are like strings wired along the edges of the screen or as a matrix in the middle, whereas CCFLs are thicker glass tubes. Also, a CCFL's inverter, which drives power to the tubes, is replaced by an LED's smaller driver board.

A compact motherboard is key. Both the TZ150N and MacBook Air fit components on both sides of their boards. The Sony's memory is upgradable via a SODIMM slot, but Apple couldn't include one because of the Air's thinness. The (6) 16 memory chips, which yield a total of 2GB of RAM, had to be soldered onto the motherboard, 8 on each side.

You commonly find low-voltage (LV) or ultra-low-voltage (ULV) processors on sub-3-pound ultraportables. Though not as powerful as standard-voltage chips, they're smaller and more energy-efficient. Their compactness opens up space on the motherboard, or allows vendors to create smaller boards. They produce less heat, so fans or heat sinks are smaller. The Portégé R500 and VAIO TZ150N use ULV Core 2 Duo CPUs, while the Fujitsu LifeBook P8010 has a 1.2-GHz Core 2 Duo LV chip. The MacBook Air's CPU is more unusual. All that Intel and Apple have said about it is that it's a (7) 1.6-GHz Core 2 Duo P7500, based on the 65-nm Merom chip. Its footprint is almost 40 percent smaller, and it's rated 15W less than a standard-voltage chip. Apple calls it a low-powered, standard-voltage chip.

Even when going small, most laptops stick with standard batteries. The MacBook Air is an exception, and its proprietary battery has its flaws. It costs $129, has a mere 37-Wh rating, is reportedly fragile, and isn't user-upgradable.

For external power, Apple used a (8) MagSafe AC adapter, to which the power cord magnetically attaches.

The Sony VAIO VGN-TZ150N and Panasonic Toughbook CF-W5 are unique among sub-3-pound laptops with optical drives in offering a cellular broadband (EV-DO) modem. Unlike the Air's, their frames are thick enough to support the modem's PCI card slot. It'll be interesting to see which laptop makers adopt WiMAX, Intel's next-generation wireless, when it's introduced later this year.

Most tiny ultraportables use 1.8-inch-diameter drives, smaller than standard, 2.5-inch notebook drives but also, at 4,200 rpm versus 5,400 rpm, slower spinning. Solid-state drives (SSDs) are the latest innovation in hard drives. SSDs come in both 1.8-inch and 2.5-inch forms. They're faster than spinning drives and should last longer, but they're still of limited capacity and very pricey. Apple offers a 64GB SSD for the Air for $999.

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