Intel said on Monday it plans to start shipping this week new processors for servers, aiming to fend off an offensive from rival Advanced Micro Devices Inc. (AMD) .

The new Xeon dual-core server processor series, which was previously codenamed Woodcrest, are the first in a range of products that use a more efficient design. Intel has said the design would enable better performance and lower power consumption.

AMD, once relegated to mimicking advances by its larger rival, has turned the tables in recent years with innovations such as putting two processing cores in a single chip, enabling it to handle multiple tasks more efficiently.

The technological edge has translated into higher market share for AMD in the server market, though Intel still outsells it by a ratio of nearly four to one in desktop PCs and nine to one in laptops.

Kirk Skaugen, vice president of the digital enterprise group and general manager of Intel's server platforms group, acknowledged AMD has gotten "a lot of buzz" in the industry but said Intel was confident of keeping its leadership position with the new chips.

"High performance computing is absolutely a key focus area here," he told a news conference. "It's an area we honestly lost share in (in) the United States over the last year, and we believe this is an exciting new product to help us win back share in high performance computing."

Intel in the past has focused on making chips that run at ever higher clock speeds, which are now measured in gigahertz, but its current top priority is making chips with a higher performance per watt.

The new Xeon 5100 series will deliver up to a 135 percent gain in performance with up to a 40 percent reduction in power use, the company said, comparing the processors to energy-efficient hybrid vehicles.

"Everything Intel is doing today is focused on delivering leadership performance without compromising power," Skaugen said. "This is a huge focus for Intel going forward."

Intel said more than 150 companies, including IBM , Dell Fujitsu and Lenovo , are planning to release over 200 server and workstation models using Xeon processors. Intel has priced the Xeon 5100 series from $209 to $851 in 1,000-unit quantities.