The FIT limiter, is a dynamic limiter of voltage and will set a different maximum for each CPU. To find out what your limit is, enable PBO to max out your TDC, EDC, and PPT limits to motherboard levels. Now temperature, FIT and Fmax are your only limiters. Use auto-overclock to raise Fmax by 200MHz, removing that barrier. Run an all core test and overserve (preferably with CPUz) what your voltage maxes out at. That is the FIT voltage, and any voltage below that AMD's algorithm deems "safe".