Socket 939 Motherboard Showdown
 

There aren't a lot of Socket 939 processors out there—the vast majority of Athlon 64 CPUs sold are the Socket 754 variety. That's sort of a shame, since the 128 bit memory interface of Socket 939 offers a nice little performance boost. We also expect AMD's desktop dual-core processors, scheduled to release in about a year, to plug into Socket 939, so it offers a clear upgrade path. Sure the Socket 939 chips are more expen-sive, but you can get an Athlon 64 3500+ for under $400, so that's no longer a great excuse.

http://www.extremetech.com/article2/...129TX1K0000532