4 Pin molex port connects to ATX Power Supply, CPU 8 Pin(4+4) port connects to motherboard, please note that the CPU 8 pin (4+4) end could not be split into 4 pin to use; Allowing you to convert molex 4 pin male to EPS-12V 8 pin(4+4) male. Mostly, EPS-12V is required by Dual, Quad CPU and Server Motherboards; With Braided Sleeves for easy cable management;