The Pentium IV embodies Intel's first new microarchitecture since 1995. It uses a very long pipeline to achieve high clock speeds: The company has demonstrated a 1.5-GHz version that could ship this year.

Those speeds will put pressure on Advanced Micro Devices. Over the past year, that company has touted Athlon as having greater frequency headroom than the Pentium III, and indeed AMD has been able to deliver significant quantities of 1-GHz chips, while Intel, until recently, has not.

With its new pipeline, the Pentium IV will take the frequency lead, forcing AMD to strain to keep up. The company says it will ship a 1.5-GHz Athlon early next year, but Intel should be able to boost the speed of its new design quickly: I expect the Pentium IV to reach at least 2.0 GHz in 2001.

AMD has also promoted Athlon's 200-MHz bus, which operates 50 percent faster than the Pentium III bus. The Pentium IV will blow by that mark with a 400-MHz bus.

Even if AMD can tweak Athlon's bus speed, it is unlikely to match the speed of the Pentium IV bus.

The question of performance remains open. Longer pipelines generally lead to lower performance per clock cycle, but the Pentium IV includes new features designed to help alleviate the problem.

Another concern is that the Pentium IV requires costly RDRAM to achieve maximum performance. If RDRAM prices come down, however, that problem becomes moot.

Intel's biggest challenge is to convince the masses that they need Pentium IV performance. The company hopes that broader use of 3-D graphics, MPEG-4 video, voice recognition and encryption, both on the Web and in productivity software, will spur demand for faster processors.

If so, PC buyers seeking speedy systems will find it difficult to evaluate the myriad benchmarks that show one system or another to be the fastest.

The race between Intel and AMD is likely to come down to who has the most gigahertz. That is a race the Pentium IV is designed to win.

Linley Gwennap is the Founder and Principal Analyst of the Linley Group (www.linleygroup.com), a technology analysis firm in Mountain View, Calif.