AMD plans to take a bite out of Intel's market share by selling energy-efficient versions of its desktop processors, the company has announced.

This month, the company will release energy-efficient versions of three chip designs: the Athlon 64 X2 dual core and the Athlon 64 and Sempron single cores.

The new chips will cost about 5 percent more than AMD's standard desktop chips, but customers will make up for that difference through electricity savings, said David Schwarzbach, division market manager for the desktop division.

AMD hopes to use these chips to duplicate the success of its Opteron chip for servers and workstations. Opteron sales have made the difference this spring in pushing AMD to post strong quarterly earnings of US$185 million in April, and driving Intel to post a drop in quarterly profit to $1.3 billion.

Many analysts expect Intel to regain its advantage when it launches its 65-nanometer Core 2 Duo chips this summer, including the Woodcrest chip for servers and Conroe chip for desktops. These AMD chips are built on a larger, 90-nanometer geometry, but offer better power efficiency, the company says.

Running at top speed, AMD's standard desktop processors draw 89 watts, while the new line of energy-efficient chips will need either 65 or 35 watts, depending on the model.

PC vendors could use the chips to design smaller, quieter computers, since the improved performance-per-watt means they can use smaller, slower fans for cooling.

"The heat, acoustics and fan speed all decrease. That is key whether IT managers are taking care of a fleet of systems, or people are trying to fit an unobtrusive PC into their living room or bedroom," Schwarzbach said.

The new designs could include set-top boxes, PC blades, or digital home PCs. Another option is the modulated system, a design that splits the computer into two parts: a small I/O port on the user's desktop and a processing module located on a nearby bookshelf or closet.

That approach can save space in cramped office cubicles and allow IT administrators to easily manage more computers, he said. Companies like ClearCube Technology already sell similar products.

AMD will ship 11 models of three energy-efficient chip designs later this month, and expects vendors to bring computers to market by June.

The 65-watt processors will include six types of Athlon 64 X2 dual core processor: model numbers 4800+ (US$671), 4600+ ($601), 4400+ ($514), 4200+ ($417), 4000+ ($353) and 3800+ ($323).

The 35-watt processor will include one type of Athlon 64 X2 dual core chip, the model 3800+ ($364), one type of Athlon 64 single core, model 3500+ ($231), and three types of Sempron, models 3400+ ($145), 3200+ ($119) and 3000+ ($101).