AMD has begun shipping two 3GHz dual-core Opteron chips, continuing a battle over multi-core processing power with Intel.

AMD plans to begin full volume shipments by early May of the new Opteron 2222 SE chip for two-processor servers and the 8222 SE chip for eight-processor servers, said Patrick Patla, director of Opteron marketing for the company.

The new chips are similar to AMD's previous top-shelf dual-core chip, but run as fast as 3GHz instead of 2.8GHz. They're for customers with general-purpose servers and workstations who need the extra speed to handle larger databases or more complex tasks.

The company did not say which vendors plan to use the new chips, but Dell, Gateway, HP and Rackable use the older line of Opterons.

AMD plans to design only one more version of this processor family, releasing a 3.2GHz dual-core Opteron chip by the fourth quarter, before committing entirely to a quad-core Opteron design called "Barcelona," due to reach markets in the middle of 2007, Patla said. AMD will continue to produce those final dual-core Opteron designs for several years to come.

When used with multi-threaded software, multi-core chips can speed computing jobs by breaking them into smaller parts and calculating in parallel. That approach can produce great results for high-end video games, but is more frequently used in servers than desktops.

Intel also plans to push its dual-core chips above 3GHz by the end of 2007, using its next-generation Penryn chip design to speed up certain chips by shrinking their transistors from 65 nanometres to 45nm, the company said last week. In comparison, Barcelona will be AMD's first server chip with features smaller than 90nm.

Even so, the new Opteron chips beat Intel's fastest dual-core "Woodcrest" processors in several benchmarks, AMD claimed in a full-page newspaper ad yesterday.

In return, Intel spokeswoman Christine Dotts replied with a single word, "Rubbish." She questioned AMD's benchmarking conditions and said that customers seeking improved server speed can buy Intel's quad-core chips for the same price as AMD's dual-core chips. Intel launched its "Clovertown" quad-core Xeon processor in November.

"We'll let the hundreds of reviewers and independent benchmarks speak on our behalf," Dotts said.