I have an ASUS TUF z370 plus motherboard, with an i7 8700k CPU, and a Chieftec-iARENA GPB-500S PSU. I have trouble connecting power to the motherboard ATX 12V slot. The motherboard has an 8 pinhole slot, while my PSU has an outlet that has only a 4 pin thingie. Is it okay to plug this in? I can provide pictures if needed. The 4 pin outlet fits nicely into the motherboard.