Can i upgrade my cpufrom fx939 pin2.1ghz

939 is is about the oldest amd single/ dual core soc.
Im afraid your a bit limmited as to the clock speed of the new Cpu.
I would take note of the board maker and its model number, then have a check on there website to see what other cpu`s the board supports. short of that its time to upgrade board and chip if your not happy with the options Armond !