Well to expand on what Czar has said a bit, I am not sure to say that its faster, cause the actual MHz can be the same, also the 939 sockets have less L2 cache. Czar said its dual channel, thats right kinda... what it is exactly is the 754 has a single on die MEMORY controller. The 939 has DUAL on die memory controllers, but only 512kb L2 cache. What the 939 offers is more memory bandwidth. Also the 939 are all Bidirectional HyperTransp0rt bus or 1Ghz in both directions. Kinda like having a 2GHz FSB, whereas the 754 were 800MHz bidirectional or 1600MHz FSB. Now as we have all learnt a long time ago more memory bandwidth means higher performance, thus it seems as though its faster. If you look at the 754 ratings vs. teh 939 ratings the 939's have lower clock speeds but the same ratings eg. a 3400+ 754 is 2.2GHz and the 3400+ 939 is 2GHz (please feel free to correct me if I am wrong I am quoting from memory). The 939's are definitely more expensive than the 754 because of this memory advantage. Czar is also right in that soon the Sempr0n will become all 754 and the 939 will rule the A64's. SO wait a lil while for the nforce 4 chipsets to come into proper mass production, look at the 939 socket A64 and enjoy.
PS the 90nm 939 A64's are faster due to the die shrink, however its more expesive by at least 20-40US. Still they are AMAZING in terms of power dissipation at 100% load. Go to the "which CPU do u prefer" thread. I put up a picture from Tomshardware showing the power consumption of various CPU's under full load. THe new 90nm process seems to have made DRASTIC improvements in power, cause even at 100% work load the 90nm A64's only consumre 34Watts of power. That translate directly into temp the core functions at keep that in mind!!!
