Davor95 :
i have kingston 4 gb x2 1333 mhz and 1.5V, is this enough to be used for this procesor and on MB LGA1151 Z170 ASUS Z170-P D3, PCIe/DDR3/SATA3/GLAN/7.1/USB 3.0? or should i buy some faster ram because i dont want to have any problems or to damage mobo or even CPU?
That RAM will not damage the MOBO or CPU, but it will kind of defeat the purpose of getting that processor. One of the main reasons for getting that processor is because it supports DDR4 RAM. Anyway, back to your question, yes that is enough RAM, but you will notice a lack in speed when multitasking heavily. I recommend 8GB, I've experienced gaming(I assume that is what you will do with the PC) with both 4 and 8 GB of ram, and the 8GB was noticeably faster.