Buying Intel's top processor may soon cease to mean buying its fastest. After years of promoting higher clock speeds as a way for users to assess performance, the chip giant is to drop megahertz as part of its processor names, instead using car-style "series" names. Chips will be classed in a series based on key features that affect performance, including clock speed.

Desktop Celeron chips will carry the 300 series name, Pentium 4s will make up the 500 series, and P4 Extreme Editions will be the 700 series. Chips debuting this year will carry the new monikers; with rare exceptions, Intel won't rename existing processors.

Within each series, Intel will assign a specific number based on features such as architecture, cache size, frontside bus speed and gigahertz, as well as relevant new technologies. In the new scheme, a 3.4GHz P4 with a 512KB L2 cache and an 800MHz frontside bus might be called a P4 540, while the same chip with a 1MB L2 cache might be a P4 550.

Intel clearly hopes the new series will lessen confusion about its Pentium M laptop chips, part of the Centrino platform, which often outperform Mobile P4s with faster clock speeds. Accordingly, Pentium Ms, which top out at 1.7GHz, will be in the 700 series, while Mobile P4s, which run at up to 3.2GHz, will be in the 500 series. Mobile Celerons will be in the 300 series.

In 2001 AMD faced a problem with its Athlon XP chips similar to what Intel has now with Pentium M. The AMD chips had lower clock speeds than Intel's top chips, but often outran them in benchmarks. AMD then shifted its naming method to one based on equivalent performance ratings, hoping to help buyers make more-informed purchases. Intel executives have the same expectation now.

One drawback to the new system, says Mercury Research analyst Dean McCarron, is that while differentiating among Intel's chips will be easier, the names will not help much when shoppers compare them with AMD's offerings. That means savvy buyers will depend even more upon test results and reviews to get the full scoop, he says.