Do I have to buy a discrete CPU fan 1 and/or 2 for AMD A10 PCU on ASRock FM2A85X Extreme 4M board? Are those fans included in PCU or MB package? Is it worth to replace them with more silent ones (if they are included)? If they are not included, what about the heat sink?
I hope you mean the CPU heatsink/fan, I believe that comes with your processor box. Motherboards do not include additional fans. In addition, you don't need to change the stock heatsink if your not overclocking. Stock clocks with the stock heatsink will do just fine. It can be worthwhile if you sensitive to how the stock AMD heatsink sounds at load, a cheap cooler to replace it can be the Hyper TX-3 or Hyper 212 EVO which are pretty silent compared to AMD's stock cooler.
I believe you will notice the noise when the CPU is at load and temperatures start to rise. I've never owned a stock heatsink but from what I hear on the threads, people complain of the stock cooler sounding like a jet engine