cheap UMPC trend. Sony, whose slim Vaio laptops command a premium, has remarked that the success of the Eee PC represents a “race to the bottom.” That is, conditioning consumers to expect very low prices could result in, well, very low prices.

The Incredible Shrinking CPU

The upcoming Intel Atom processor highlights an important driving force behind the UMPC frenzy. The rise of these ultramobile PCs isn’t merely random, but enabled by CPUs that are squeezing more speed and using less power than ever before.

Today’s UMPCs, like the Eee PC, Classmate, and HP Mini-Note, are still built around last-generated mobile processors like the Intel Celeron M and Via C7. Although these processors offer decent speed, their power consumption can be problematic: One of the few criticisms of the Eee PC is its relatively short battery life of under three hours.

There is considerable debate over how much of a performance advantage the Atom will offer when it is available in mid-2008. Early reports suggest it may not be significantly faster than the Celeron M, but it does offer hyper-threading to support a virtual second processor. But most importantly, the Atom is expected to provide major gains in battery life, possibly more than five hours depending on battery configuration.

Although mobile processor roadmaps are still in their infancy, it is already anticipated that near-future iterations from both Intel and AMD will bundle an increasing number of functions into ever-shrinking processors. Wireless connectivity is already integrated into the Centrino Atom, and some expect to see graphics integrated soon.

AMD’s Geode mobile platform is currently used in the XO laptop, which delivers the longest battery life of current-model UMPCs. Geode integrates a large chunk of system integration into one embedded processor, translating into significant power efficiencies. But the current Geode platform is noted for its lackluster performance, which is consistent with criticism of the XO for being among the slower UMPCs despite its impressively modest power demands.

Trading Platters for Circuits

The rapidly emerging maturity of solid state storage (SSD) is also allowing UMPCs to lighten their load, both in weight and power. Traditional hard disks are large, relatively speaking, even when they’re small. It also takes a lot of power to keep their platters spinning.

In contrast, flash memory involves no moving parts and weighs mere ounces. It’s no surprise, then, that the Eee PC, XO, and Classmate PC all use flash memory rather than hard disks. But flash memory is expensive: 64GB of solid state memory costs more than $1,000. A similar capacity hard disk, even a tiny 1. 8 inch model, costs one-tenth that.

As a result, today’s low-priced UMPCs generally come with between 2 and 8 GB of flash memory, which doesn’t offer a whole lot of storage space. Of course, you can always add more flash by inserting a memory card or USB stick. And you can connect a USB hard drive for generous amounts of conventional storage.

Besides cost, SSD and hard disks share dissimilar performance characteristics. A hard drive is slowest when it first accesses a file—the so-called “seek time”—because its head must physically move to a certain location on the platter. The fastest hard