Hello guys 
Im on ASUS ROG Crosshair VIII HERO (WIFI). User manual clearly told what we cant connect only 4 pin, but we can connect 8 pin OR 8 pin plus 4 pin.
So it looks like 4 pin are not neccesary for proper working and they are optional. Also a lot of people told what those extra 4 pin are neccesary only if you OC you processor.
But what exactly whose "OC" means? Does AMD PBO are already count as a OC? Or OC means manual push of voltages and so on to higher amount?