Just as a word of caution, make sure the Opty 185 will actually work in your particular S939 system before you root around and buy one. Not all S939 motherboards will recognize the second core on the CPU. Really depends on the chipset of your particular motherboard AND whether the BIOS will recognize more than 1 core.
I recall having a S939 motherboard with a chipset that supported 2-core procs, but the BIOS did not (and the vendor never made one). I did eventually put together an Opty 185 system that my nephew in WV now uses as a gaming platform. Actually a pretty decent performer when coupled with a decent GPU (his is a Radeon HD 2600XT). Good luck! HOOAH!!!