The main difference is the memory interface where the 754 is 64 bits wide and the 939 is 128 bits wide. You can see more here:
http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_9485_9487%5E10248,00.html
Based on that the 939 socket will perform faster in terms of memory bandwidth. If you are doing memory intensive computing then opt for the 939. If the applications you are running are hitting the hard drive a lot i.e. video capture/editing then you may not see as big of a difference. I did read on Tom's Hardware that they thought the 754 socket would be phased out and recommended that if you had the money to opt for the 939. Not sure on this as they (AMD) released a Sempron for the 754 socket. I went with the 754 3000+ to run my linux server at home. I may turn it into a Freevo/Myth box at some point but the memory bandwidth wasnt really an issue for me.
-Dan
Hey guys,
I'm purchasing a new computer but i'm upgrading the motherboard and processor. And soon enough I realised that there is either socket 754 or 939 for motherboards and CPUs. I understand that they need to be both the same sockets but what is the difference between these two sockes..?
The processor = AMD Athlon 64 Bit 3500 Socket 939 or 754 with Fan
The motherboard = Gigabyte GA-K8NSNXP nForce 3 Chipset .... and that comes in both 754 and 939.
939 is more expensive, i'm guessing it's the better one. Thanks guys, any answers will be appreciated.

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