AMD is planning to add a triple-core desktop processor to its current dual-core and forthcoming quad-core desktop processor line.

The triple-core processor features the same design as the quad-core model, and both are based on the Phenom architecture scheduled to ship in the first quarter of 2008.

Intel is currently the only chip maker offering quad-core desktop processors, and has made no public mention of plans to ship a triple-core processor.

An Intel spokesperson declined to comment on whether the firm was preparing such a product.

AMD argues that triple-core processors are appealing because their quad-core peers are too powerful for the average desktop. Market share data indicates that quad-core processors have captured less than two per cent of the desktop market.

"Our native multi-core design will deliver a more seamless array of products, serving a broader swathe of the market," Bob Brewer, AMD's corporate vice president for marketing and strategy, said during a meeting with reporters in San Francisco.

An alternative explanation to the limited demand for quad-core processors could be Intel's pricing.

The firm currently prices the chips at a significant premium over dual-core models, although prices have dropped rapidly in recent months.

But AMD still maintains that the average user will not derive much benefit from four cores, because most of today's software is designed for execution on a single thread or processor core.

The few exceptions, mostly games, will often use a maximum of two cores. While a security scan from antivirus software can take up a third process, the fourth core will typically sit idle.

A triple-core chip would also be smaller, decreasing the chance of defects during manufacturing. The resulting increase in chip yields will boost revenues.

AMD declined to address pricing or clock speeds for its triple-core and quad-core processors.

Nathan Brookwood, an analyst with Insight 64, suggested that reducing the number of cores could allow AMD to run its desktop processors at higher clock frequencies.

Desktop processors are typically designed to consume no more than 120W. A core reduction frees up capacity for the three remaining cores, and Brookwood estimated that this could result in a 10 to 15 per cent overall performance boost.

Because most software is designed for single-core processors, three faster cores could outpace four slower ones in real-world applications.

"If AMD can make a triple-core that runs at a substantially higher clock frequency, that is going to a be really fascinating trade-off," said Brookwood.