well it depends of which fermi you talk. cant stand the power figures of the 465/470/480. the 460 is still not up to 5xxx series standards, but a good chunk of move in the right direction.
http://tpucdn.com/reviews/Palit/GeFo...s/perfwatt.gif
that graph kinda puts it in your face.look around and above the '100%'
what you see is ati, and one nv(well 768 and 1gig versions of the 460)