SAN JOSE, Calif. — Advanced Micro Devices and Intel Corp. will square off over quad-core processors this week as each side tries to position itself as leading the race for multicore x86 processors.

Intel is expected to demostrate at the Intel Developer Forum Tuesday (Sept. 26) its Clovertown and Kentsfield server and desktop processors which essentially pack two existing dual-core server or desktop chips inside a multichip module. Intel is expected to demo working versions of the chips and share some information on the performance, power and availability of the CPU.

Tom's Hardware Web site described Kentsfield as a 2.6-GHz chip with a 1.3-GHz front side bus. It has one 4-Mbyte shared L2 cache per die and four 32-Kbyte L1 caches per core. The chip was found to be in a B revision and fifth stepping.

By contrast, AMD will ship quad-core Opteron server CPUs in mid-2007 that link four cores on a single die. That reduces latency Intel's parts will exhibit when a core on one die has to go through an off-chip memory controller to talk to a core in the other die, said John Fruehe, AMD's business development manager for Opteron.

AMD uses the cache coherent HyperTransport bus integrated on its CPU cores to link each core on a single die.

Unlike Intel, AMD will not be ready to demostrate its quad-core CPU or deliver performance data on it until the end of the year. "We taped out the processor, I believe, in August," Fruehe said.

AMD will have quad-core products that fit into the same power dissipation specs as its existing dual-core CPUs—120W, 95W and 68W. Intel's quad-core parts could consume 20 to 50 percent more power, Fruehe said.

An Intel spokesman said the company's quad-core CPUs will not consumer more power than its Pentium D Extreme Edition, the last of the line of high-end, single-core desktop CPUs. Like AMD, Intel offers its processors at several power consumption levels.