|" formula V is a high end mobo and 8g is enough"|
You came here asking for help & have provided minimal info. If you want help you need to respond to the followup questions.
It doesn't matter if you have 4GB, 8GB, 12GB, etc. You didn't state which speed/voltage you are going to use. If you get the wrong RAM, it will limit how much you can overclock. And the RAM voltage is important. DDR3 RAM that conforms to the JEDEC standard runs at 1.5v, but there is other RAM out there that requires higher voltages. Why? Because it's not what is says it is & needs to be overvolted to run stably. You said you never overclocked before so I suggest you do some reading before you muck up your "high end mobo".
BTW, I hope you got a decent quality high end power supply to go with it. I'd ask which one but I doubt you'd give a straight answer.