If you compare a 939 and AM2 processor, say the X2 3800+, you wont notice a difference, but the AM2 platform has alot more newer CPU's for it, and will be AMD's standard for a while. It also has DDR2 support.
thanks
im just trying to build a new computer at the moment, ive noticed that am2 is alot cheaper than the 939, i dont really care about the easier up grade later on, i just thought that 939 would be better
The reason AM2 is cheaper is because thats what AMD is producing now. 939 CPU's arent being produced AFAIK, so therefor they are more rare and have a higher price.