CPUs Cut The Power

New processors will boost mobile computing performance while consuming a fraction of the power of traditional designs.

When Bristol-Myers Squibb Pharmaceuticals U.K. Ltd. in Middlesex, England, first migrated its sales force to notebook PCs in 1996, the two- to three-hour battery life caused frequent interruptions during sales calls. Not surprisingly, many salespeople went back to paper presentations. That's changing today, as new low-power processors emerge that let mobile computer users do more while consuming less power.

New technologies are driving the power requirements of microprocessors ever lower—even as their capabilities increase. In the short term, users of mobile devices are enjoying longer battery life, but in the long term, these low-power designs will lead to new applications and new ways of using portable computing and communications gear.

Intel Corp., which has developed more than 50 processors just for notebook computers, recently announced its first 2-GHz mobile processor, the Mobile Intel Pentium 4 Processor-M. Intel says the CPU will enable a laptop computer to run several applications at once while also running background tasks such as encryption, compression or virus scanning.

Intel's next-generation microprocessor, code-named Banias, will be the first designed from the ground up for notebook computers. The company says Banias will be the highest-performing and most power-efficient chip ever produced for notebooks when it debuts next year.

But Intel has no monopoly on power-saving CPUs. Advanced Micro Devices Inc. in Sunnyvale, Calif., offers low-power versions of its Athlon and Duron lines of notebook processors. And late next year, the company plans to introduce its low-power ClawHammer processor based on more energy-efficient 0.09 micron technology.

IBM's announced PowerPC 405LP features "ultra-low-power operation" for use in portable devices such as personal digital assistants (PDA). Its ability to scale voltage and frequency almost instantaneously with the needs of the application will enable new capabilities for PDAs, such as audio and video, says Lisa Su, director of emerging products at IBM Microelectronics. "That happens in software," she says. "As soon as the song finishes, I ramp down to the lowest power consumption."

While Intel, AMD, IBM and others use power-saving techniques that are similar in concept, Transmeta Corp. in Santa Clara, Calif., takes a different path with its "code morphing" technology. Its Crusoe processor consumes up to 70% less power than comparable Intel x86 processors and enables all-day battery life in some notebooks, Transmeta claims.

Processors that consume small amounts of power will enable tiny devices to run full-blown operating systems, such as Windows XP, and so will be able to run more applications, says David Ditzel, marketing vice president at Transmeta. And he says wireless networking is leading to new usage patterns, such as carrying a computer to meetings all day. That requires longer battery life and lighter weight.

Current power improvements were enough to convince Bristol-Myers to purchase Sony Corp.'s Crusoe-powered Vaio C1VE PictureBook. "Our requirement was to provide five hours or so of life to the mobile sales force without recharge." says David Hurst, head of IM and telecommunications. With improved processor designs on the way, Hurst may just need to raise his expectations.



Where the Juice Goes

Chip vendors are spending millions of dollars to extend battery life by making microprocessors more power-efficient. But according to Intel, the CPU and its associated chip set account for only about 10% to 25% of a portable computing device’s total power consumption. The biggest power hog is the display, which in typical usage consumes about a third of total power. Here’s a breakdown of power use by a notebook PC equipped with a Mobile Intel Pentium 4 Processor-M.

Where the Juice Goes

Source: Intel Corp. Mobile Products Group


Copyright © 2002 IDG Communications, Inc.

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