I am having trouble finding out.
From this article, it looks like the memory interface is the only difference.
Mr2001 that article you have posted is somewhat outdated. Current Athlon 64’s and Athlon FX’s have both moved to the same Socket 939 interfaces, so the only difference is the FX series has an unlocked multiplier (which makes overclocking easier.) Otherwise, at the same clockspeed/cache amount, a socket 939 Athlon 64 will be just as fast as the equivliant FX.
And Muad’Dib , if you are thinking of building a new machine, definatly take a look at the Athlon 64 x2 processors - as the name implies, they have two full processor cores on board.
I need a bucket for my drool. 
(One day…hopefully before the rest of the world in onto quad-core CPUs…I will have one…)
Yes, but they are very expensive and all of the reviews I have seen show that, outside of multi-tasking, they have middling performance.
So if I were able to overclock it enough, I would get the same performance from a Athlon 64 3700+ as from a FX-57?
I might be mistaken but doesn’t the FX work in SMP configurations wheras the 64 is limited to a single chip (on which there might be multiple cores).
Duh, never mind, I was thinking of the opterons.
Bump.
bu-da… BUMP!
Have you tried the AMD forums?