AMD Athlon64 X2 4800+ 65nm Processor
 

To further combat excessive power consumption, Intel redesigned its processor architecture completely. AMD on the other hand just tweaked its K8 architecture for more efficiency. The Socket AM2 Athlon64 X2 4800+ processor is one of AMD's 65 nanometer parts, moving it onto a smaller manufacturing process has helped AMD cut power consumption rates to 65W. The Athlon64 X2 4800+ idles 13W less than the X2 5000+, and 20W lower than the single core Socket 939 Athlon64 4000+. It's under load where we see the real power savings

http://www.pcstats.com/articleview.cfm?articleID=2095