Last month, AMD launched the Phenom II X4 processor line-up, and with it ushered in the first desktop processors built using the company's 45nm process node. While the first two Phenom II processors to arrive, the 3.0GHz X4 940 and 2.8GHz 920, were clearly superior to previous Phenoms in terms of performance and power efficiency, and they remain the two most powerful processors in AMD's product stack today, they did not exploit all of the capabilities offered by their newly tweaked, and redesigned cores.

You see, the AMD Phenom II X4 940 and X4 920 were designed for the socket AM2+ platform, and as such, they supported only DDR2 memory. The latest additions to the Phenom II line-up, the Phenom II X3 720 Black Edition and X4 810, however, are designed for the AM3 platform. That means these new chips can work not only in existing AM2+ motherboards with DDR2 memory, but in new AM3-based motherboard with DDR3 memory as well. The flexibility of these new socket AM3 based Phenom II processors should appeal to existing AMD system owners who may be thinking about a CPU upgrade, or potential new AMD-based system buyers who want the freedom to choose from a wide array of motherboards and memory type at multiple price points.

We've taken the new triple-core Phenom II X3 720 Black Edition and quad-core X4 810 for a spin through the lab using both socket AM2+ and socket AM3 based motherboard platforms, to give you all an idea as to how each configuration performs. Read on for the full scoop...