The single-core processor is apparently all but history, as major server vendors this week have been announcing plans to use the new generation of Intel's dual-core chips.

For example, HP by late June will largely "have dual-core capability across the entire set of processors, from the least expensive processors all the way to the top end," said John Gromala, director of server product marketing. HP's single-socket systems will be updated later this year with dual-core capabilities.

HP plans to release new ProLiant and BladeSystem servers next month in seven of its server models and make Intel Xeon dual-core chips the dominant processors on its two- and-four-way server-line products. According to HP, users will see a tripling in performance -- not only from the processors but also because of a redesign of the subsystems, including memory, storage and management controllers to take advantage of the chip capabilities and power management functions to reduce power use during off-peak periods. HP's new DL360 system, for instance, will support six drives, up from two.

IBM also announced products this week that use the new chip, as did Rackable Systems.

With other hardware makers touting similar plans, Intel officials expect that by the end of this year, 85 per cent of the processors the company ships will be dual-core chips, said Scott McLaughlin, an Intel spokesman.

The Intel Xeon dual-core Dempsey 5000 series of chips was available in March. And in late June, server vendors are expected to begin shipping hardware that uses the Intel Xeon dual-core 5160 Woodcrest processor, which has about 3.1 times the performance of the Intel Xeon single-core processor.

Jonathan Eunice, an analyst at IT research firm Illuminata, said dual-core systems do deliver a performance boost because of their ability to handle multi-threaded applications, which can be bandwidth-intensive. While single-core processors have experienced big increases in speed, they don't always easily handle "interrupts" -- software requests that require the immediate attention of a processor. That's where a dual multi-thread capability helps, Eunice said.

While many business applications aren't optimised to take advantage of parallel environments, the middleware, databases and Web servers that those applications use can see an overall performance boost from multi-core systems, Eunice said. "The system may seem much more responsive because more things can happen in parallel, but individual applications are not necessarily going to run any faster," he said. "Many applications will never be multithreaded themselves, they will always rely on the middleware to do it for them."

Multi-core systems are the only types of servers that Austin Energy now buys, said Andres Carvallo, CIO of the city-owned energy company in Texas. "Multi-core servers are key in n-tier environments," he said, referring to environments where an application is distributed among separate computers, such as one for the database and another for the business logic.

He noted that Java and Oracle are multithreaded environments: "The more cores you have the better performance."