Intel on Friday expanded its line of Xeon quad-core processors with the introduction of two energy-efficient chips targeting a growing demand for server processors that use less power and produce less heat, thereby reducing electricity and cooling costs.

The 50-watt L5320 and L5310 operate at 1.86 GHz and 1.60 GHz, respectively, and feature 8 Mbytes of on-die cache for faster memory data communication. The chips run on dedicated 1066-MHz front side buses. In 1,000-unit quantities, the L5320 is priced at $519 each, and the L5310 at $455.

The processors can be coupled with Intel's Bensley server platform and are designed to be drop-in compatible with existing Xeon dual-core and quad-core chips. The new chips represent a 35% to nearly 60% decrease in power consumption from Intel's existing 80-watt and 120-watt quad-core processors.

Servers based on the new products are expected to be available worldwide over the next few months from Acer, Dell, Digital Henge, Fujitsu Siemens, Hewlett-Packard, HCL, IBM, Rackable Systems, Samsung, Verari, Wipro, and other companies.

Intel, which plans to officially announce the new offerings Monday, said the latest processors are designed for blade serves and other computers found in high-density data centers. Such environments are commonly found among large Internet companies, such as Google and Yahoo, and financial institutions. These companies are willing to trade less power per processor for lower energy consumption to reduce costs for electricity and cooling. Faster chips run hotter.

When used to replace older technology, Intel's quad-core processors, coupled with virtualization technology, can reduce costs by $6,000 per year over the lifetime of a server, according to the chipmaker. The company also claims to have reduced power consumption in its server processors tenfold over the last 18 months. Since November, Intel has introduced 11 server, workstation, and desktop PC quad-core processors.

This article was edited on March 12 to correctly identify the processors as quad-core.