Intel has begun phasing out several of its mobile processors, paring down a crowded, confusing line-up to one dominated by the Pentium M processor.

The company issued a Product Change Notification on Friday telling its customers of the changes. The Mobile Intel Pentium 4 and Mobile Intel Pentium 4-M processors will be gradually taken out of Intel's product line over the remainder of 2004. Only three Mobile Intel Pentium 4 processors that were built on the company's 90-nanometer process technology will be available after November; all other mobile processors in Intel's lineup will be based on the Pentium M architecture.

The Mobile Intel Pentium 4 and Mobile Intel Pentium 4-M are designed for the desktop-replacement notebooks that have captivated consumers over the past year. They are based on the same architecture as the desktop Pentium 4 processor but feature some added characteristics to help manage power consumption.

The brands evolved as Intel switched from the Mobile Pentium III family to the Pentium 4 family, said Dean McCarron, principal analyst with Mercury Research. The Mobile Intel Pentium 4-M was the first mobile processor of the Pentium 4 generation, but its introduction came well after the desktop Pentium 4 first appeared, he said.

During that gap, notebook manufacturers started to use desktop processors in notebooks to fulfil the demands of users who wanted as much performance as possible at the expense of portability and battery life. These so-called desktop-replacement notebooks have been very popular among consumers over the last two years.

Mobile processors are higher-margin products than desktop processors because of the additional features, McCarron said. So Intel designed the Mobile Intel Pentium 4 to fill that need of desktop-replacement buyers while still taking advantage of the higher margins on notebook chips, he said.

The fact that some desktop processors had to sharply reduce their clock speeds to prevent overheating in several notebooks helped Intel make the case for a mobile processor with desktop-like performance characteristics, McCarron said.

But with three premium processor brands with similar sounding names, Intel's mobile processor lineup has been confusing for potential notebook buyers, McCarron said. Intel also sells a Celeron version of the Mobile Intel Pentium 4 chip, adding to the complexity.

When it introduced the Pentium M processor in March of 2003, it posted several benchmark results that showed the Pentium M outperforming its Mobile Intel Pentium 4 and Mobile Intel Pentium 4-M counterparts, McCarron said. Higher-priced desktop-replacement notebooks will likely take advantage of that increased performance, while cheaper notebooks have the option of Intel's new Celeron D processors, he said.

The chips slated for retirement in the Mobile Intel Pentium 4 lineup are the 3.2GHz processor with hyperthreading, the 3.06GHz processor with hyperthreading, the 3.06GHz processor, the 2.8GHz processor with hyperthreading, and the 2.8GHz processor. The Mobile Intel Pentium 4-M processor family will lose all four remaining chips in that lineup, ranging from the 2.6GHz processor to the 2.2GHz processor. The Mobile Intel Celeron processors at 2.5GHz, 2.4GHz, and 2.2GHz will also be discontinued.