i think people are describing them as been the same is that both sockets contain a similar series of cpus. also dispite the name they both have the same number of pins but are arranged differently. the 479 is for a mobile platform used for p4m up to c2d and the 478 was the old desktop socket before intel moved to LGA775. not sure though because i have come across a 479 mFCPGA but not a 478 just asumed you made a mistake