You are mixing all up
First of all what is the exact name of the board that ends with the UD3 suffix ?
Secondly what is the revision of the board ,so you know what BIOS to install ?
Take a look at the left lower corner of the board ,as you consider the CPU socket on the top side.
Each hardware version has a specific set of BIOS to install.You will not be able to install BIOS-es from revision 3 for older revisions.
For flashing use the Q-Flash feature if possible.
You can flash to latest BIOS with a supported CPU ,something like a Athlon 2 or Phenom 2 CPU .
Theoretically the version 3.0 of the AM3+ AMD 9xx chipset based boards should take the FX CPU-s with no problems whatsoever depending on the TDP wattage supported.