Im late. i now, sorry for that but i think that M5A78L-M LX3 only supports CPUs of 95w, the FX-8300 needs 125w. You can have some problems with your baseboard if you did purchased it and put it on. I´l recommend selling that FX-8300 and picking a FX-6300. Its better to pick another baseboard (like the M5a99fx Pro R2.0), if you cant you should pick the FX-6300