Ohhh, FX series CPU . . . loved those times very EZ to OC. Those CPUs at the time were a little funky so..... depending on it and the RAM if you have enough power to keep it at 1600MHz is the thing. I had an FX-4100 OCed to 4.4Ghz with 1866Mhz RAM solid but just cuz I think I had the right power and colling for it. Idk how it works anymore; been years since I used it. Also, that 4 pin CPU power is just for the cooler not the it itself meaning your cooler has fan control on it's own. It probably doesn't matter it it's underclocked cuz it's gonna do that regardless if it does say it's at forced 1600Mhz. You can try other methods but to relate I also had DDR4 RAM that should've been 2400Mhz but underclocked to 2133 for CPU purposes idk why I just go by the facts lol............................