Need help on proccesors?

I got a Socket 939 motherboard that currently has AMD Athlon 64 3400+ 2.2Ghz proccesor. I was looking around and i saw i can get a dual core proccesor for 939 socket for like £30-£40.

Would Athlon 64 X2 4800+ 2.4Ghz work on my motherboard? It has the same 939 socket but i am not sure that it will work 100% lol

If it would work will i get a good ammount of boost in my CPU performence?

Thx for any help

Manufacturer: NEC COMPUTERS INTENATIONAL

Model: MS-7168 1.0

Would Athlon 64 X2 3600+ also work?

Thx for any help

http://support.packardbell.com/uk/item/index.php?i=spec_orion&pi=platform_honeymoon_imedia

If the above link is the right mobo, its not compatable with dual core processors, only single 939's and FX series 939.