Intel's Dothan prepares for May debut

Intel is to introduce its Dothan mobile processor on 10 May.

Intel is to introduce its Dothan mobile processor on 10 May.

Dothan is the codename for the 90-nanometer version of the Pentium M processor, first introduced under the Banias code name last year. The Pentium M, along with a mobile chipset and a wireless internet chip, makes up Intel's Centrino mobile package for notebooks.

Intel doubled the amount of Level 2 cache that comes with Dothan to 2Mbytes.

The jump to a 90-nanometer process technology allows Intel to decrease the size of the transistors on the chip. This means the company can add transistors to improve performance without having to make the chip bigger.

Intel has already shipped the Prescott Pentium 4, its first 90 nanometer processor for desktop PCs. That chip consumed more power than its Northwood predecessor, and there are some concerns that Dothan might duplicate that power consumption increase because of  the additional cache as well as excess power leakage from chips made on the 90-nanometer process generation.

Power consumption is a much more important consideration for notebook designers since both battery life and mobility are affected by chips that consume excess power.

Anand Chandrasekher, vice president and general manager of Intel's mobile processor business, has said Dothan will provide the same amount of battery life as the Banias Pentium M chips with better performance.

An increase in cache size requires more power to feed the additional transistors, but there are several things Intel can do from an architectural design point of view to manage that power, said Dean McCarron, principal analyst with Mercury Research.

The Banias Pentium M processor was a good example of well-managed power consumption, and Intel will probably employ similar and more sophisticated management techniques to deal with the power consumed by Dothan's larger cache and possible current leakage, McCarron said.

Later this year, Intel will pair Dothan with the Alviso chipset and new dual-band wireless internet chips to create Sonoma, the code name for the next-generation Centrino platform. Alviso consumes less power than existing Intel mobile chipsets, and Sonoma will also include technology that helps reduce the amount of power consumed by a notebook's display.

Dothan was supposed to have been launched in the first quarter, but was delayed when the company had to modify some circuits on the chip to make sure it could be manufactured in high volumes, Intel president and chief operating officer Paul Otellini said earlier this year.

Dothan will also be the first chip launched since Intel decided in March to adopt a performance numbering scheme. All future Pentium M chips will fall into the 700 series, and Intel will rate chips based on a number of factors, such as clock speed, cache size, or other features.

Tom Krazit writes for IDG News Service

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