SilentPCReview tries to answer an important question: what is the best power efficiency achievable with currently available AMD and Intel processors that can be used on a desktop PC? The answer: "Our focus on thermals, power and energy efficiency led to mostly predictable results: mobile processors are best, followed by AMD desktop processor in general, and then Intel desktop processors. The power efficiency of AMD Athlon 64 single and dual core processors is excellent, even for their highest performance models. The Intel desktop processors suffer from inefficiency, even on the 65nm die. The Core Duo is a delightful exception in Intel's camp, with probably the highest performance-per-watt ratio of all the processors in our survey."