The latest shoe to drop in the race toward multicore technology came today from AMD, which says it has demonstrated a working dual-core version of its Athlon 64 desktop processor.

"We're in production," says Teresa deOnis, AMD's manager of branding. "We will have availability in the second half of 2005--that's when it will be in PCs on store shelves and in the hands of system builders."

The dual-core Athlon 64 is being fabricated in a 90 nm semiconductor process at AMD's manufacturing facility in Dresden, Germany.

Today's announcement is the latest in a long-running battle of one-upmanship between AMD and Intel. The two companies have been vying for multicore mindshare since last year, when both firms pledged to release dual-core versions of their respective processors.

Multicore chips place two or more CPUs on a single piece of silicon. They are seen as the solution to power-consumption problems that have come to the fore as clock-speeds have increased beyond 3.0 GHz. At such speeds, single-CPU processors can often dissipate more than 150 W. In contrast, dual-core parts can reduce power consumption to more reasonable levels. For example, a processor with dual 2.0-GHz cores can deliver performance not all that different from a single-core 3.5-GHz part. More important, such a dual-core part will hold down power dissipation to a figure closer to that of a standalone 2.0-GHz CPU, allowing processing throughput to effectively double for not much more power.

Earlier this month, Intel said that it will ship its first dual-core Pentium processors in the second quarter of this year.

On the server front, AMD says a dual-core version of its 64-bit Opteron server processor is already in production and will be available in the middle of the year. Intel plans to ship dual-core implementations of its high-end Itanium processor sometime this year. Dual-core versions of its mainstream Xeon server processor are due in the first quarter of 2006.