Intel, the world's top chipmaker, on Tuesday released its first high-end models with 64-bit features that accommodate a large amount of memory.

Intel unveiled the processors in San Francisco with top server executives from x86 server market leader Hewlett-Packard, Dell, IBM and Unisys. The chipmaker also began selling an accompanying chipset that connects the processors to the rest of the system and means the improvement of the memory, data transfer and input-output features.

The new Xeon MP models are designed for servers with four processors. There are two new Xeon MP varieties: the cheapest "Cranford" with 1MB of high-speed cache memory and the more powerful "Potomac" with 4MB or 8MB of cache.

Intel rival Advanced Micro Devices (AMD) is leading the 64-bit extensions to such x86 processors and already sold 64-bit models for four-processor servers. It hopes to leapfrog Intel again by introducing dual-core processors, which employ two processing engines on each slice of silicon.

Intel's dual-core processors are scheduled to arrive in early 2006, according to Jeff Richardson, general manager of Intel's Server Platforms Group.

The arms race is a new feature for the x86 server market, on which customers spent 6.1 billion dollars in 2004, according to market researcher Gartner.

Intel controlled the market for most of the past decade since the company introduced its first server-oriented product, the Pentium Pro, for dual-processor machines, while AMD is chasing closely. Both hope to grow at the expense of processor alternatives such as Sun Microsystems and IBM.

Customers should be able to upgrade the new servers introduced Tuesday with dual-core processors coming in 2006, said Pat Gelsinger, senior vice president of Intel's Digital Enterprise Group.