Most business users today rely on two-socket systems, so moving to eight sockets is a big step up. Analysts said eight-socket models are a tiny part of the x86 server market, and not all vendors sell them. IBM sells eight-socket x86 systems. However, Hewlett-Packard Co. last year dropped an eight-socket system it had introduced in 2003.

The new Sun Fire x4600 runs Advanced Micro Design Inc.'s Opteron chip, which can scale from two to eight sockets. It's "really a virtualization platform that allows customers to consolidate dozens or more conventional two-socket systems that never get fully utilized," said Andy Bechtolsheim, Sun's chief architect and senior vice president for network systems.

Bob Pappagianopoulos, corporate director of technical services and operations at Partners HealthCare System Inc. in Boston, said he hasn't needed to go beyond four sockets for any of his x86-based applications. But the health care provider is testing virtualization, and that could lead to the use of larger servers to support multiple applications, Pappagianopoulos said.

"If we're successful on putting many applications on a four-way, then we may look to expand," he said. "But I don't see us doing that in the next one to two years."

Charles Orndorff, vice president of infrastructure services at Crossmark Holdings Inc. in Plano, Texas, is a user of HP's discontinued eight-socket system who has switched to buying HP's four-socket, dual-core systems. Although pleased with the four-socket performance, he said he isn't ruling out the need for eight sockets at some point, but he quickly added that quad-core chips are coming.