The Phenom II is AMD's crème de la crème microprocessor; 45nm silicon, the best clock speeds, the largest caches, and the largest number of processing cores. While these attributes have made the AMD Phenom processor line a darling amongst AMD enthusiasts and overclockers, there is a dark side to the Phenom which is manifest in relatively poor power efficiency and high heat output. Today, AMD seeks to shift that tide with the introduction of the energy efficient AMD Phenom II X4 910e processor for socket AM3.