What version do you have on the bios? You need a minimum of v1006 (this was a beta version - 1201 was the stable release) to support the processor - And they are currently on V2501.
If you have an older AMD processor, can you give that a try? You would be able to update the BIOS with the older processor. I have that exact mobo and and FX-8320, and I had to update the BIOS prior to utilizing the processor.
If you don't have access to another processor, most computer stores (not BEST BUY) will be able to flash the BIOS for $25 - $50.