Ultramobile PCs, the new product category developed by Microsoft, have been unsuccessful because they're too expensive and their batteries don't last, according to AMD.

AMD is exploring the prospects for ultramobile PCs, which include Samsung's Q1, but wants to be sure they make sense for users before making a big commitment, said Phil Hester, AMD's chief technology officer.

The devices are currently more expensive than many laptop PCs and their batteries don't last very long compared to other devices. They also need new screens that can be viewed outdoors under the glare of the sun, according to Hester.

"We have a processor for that space when the space is ready," he said.

Most of the big design wins for ultramobile PCs have gone to Intel and Via Technologies, which may help to explain Hester's coolness to the market. Samsung recently announced a new version of the Q1, called the Q1 Ultra, which starts at about US$800 and uses Intel's new McCaslin processor. The new Intel chip should improve battery life considerably over the previous model, from 1.5 hours to more than 4 hours, according to Samsung.

But AMD has had some design wins too, with its Geode processors. Raon Digital, a South Korean company, uses the Geode LX800 in its Vega ultramobile PC, and has put an LX900 in its Everun, which hasn't been launched yet. The Vega boasts 6-hours of battery life, while the Everun lasts seven hours on its standard battery, or up to 12 hours with an upgraded battery pack.

Besides ultramobiles, the Geode family is aimed at low-end laptop PCs and the high end of the handset market, Hester said.

There's a Geode processor in Nicholas Negroponte's One-Laptop-Per-Child laptop. The OLPC project is trying to reduce the cost of its laptop to US$100 and put it in the hands of school children in the developing world.

Hester believes the battle to put the next billion people on the Internet is not going to be won by PCs, however.

"I really think for most people, the device is going to be the handset," he said.