In addition to adding two more cores, AMD is adding power management technologies and improvements to boost the chips' performance, said Margaret Lewis, a product marketing director in AMD's server and workstation division. The company hopes the Istanbul chips will deliver improved performance while drawing the same amount of power as existing quad-core Shanghai server chips.

The Istanbul chips are based on the Shanghai core, with the "same energy efficient parts" and additional cache, Lewis said. She didn't provide further details of the technologies, but said the tweaks should help the chip handle heavier processing loads.