Here's good news for those who want to green their data centers: The new generation of AMD Shanghai quad-core processors include unique energy-savings features that can cut energy costs, while increasing server power.

AMD introduced its 45nm Quad-Core Opteron processor (which were codenamed "Shanghai") last November. Since then, it's worked to cut energy consumption, and yesterday announced two new Shanghai processors, the AMD Opteron HE, desgined mainly for energy efficiency, and the AMD Opteron SE, designed for the data centers that require as much computing power as possible.

At the core of energy savings is a new feature called AMD PowerCap. In his blog, John Fruehe Director of Business Development for Server/Workstation products at AMD, says PowerCap:

will allow IT datacenter managers to set predefined maximum limits for the processor’s clock speed and voltage, allowing a flexible solution for holding down energy costs. Because many workloads tend to be spiky in nature, the need to run at the highest clock speed is often only for a cycle or two. Power capping helps smooth out the peaks and can help maintain a better overall average power. In fact, AMD PowerCap manager can reduce server processor power consumption by up to 63%. And our AMD CoolCore technology, which lets you turn off unused parts of the processor, is now extended to include L3 cache.

That's potentially some very significant power savings. Fruehe later claims in his blog that the Shanghai HE delivers up to a 44% improvement in performance to power compared to the previous Shanghai generation of processors.

HP, Dell, and Sun have already announced servers based on the new processors.