Power supply comes with two motherboard power headers



Are you sure you have the ranger? That has only an 8-pin EPS header and a 24 pin motherboard header. Either way, the 8 pin will have to be plugged in, as it provides power for the CPU. Some cheaper motherboards have a 4 pin EPS connector because they do not provide extra power for overclocking. As such cheaper PSUs only have a 4 pin as well.

Since your motherboard is a high-end model, it has a 8-pin EPS header to provide plenty of overclocking headroom for high end CPUs. It has to be plugged in, else the PC will not function properly.
 
Yeah, man, I'm sure.

I didn't mean the m/b, I meant the cable that came with the power supply. 24pins + 10 pins (split). All I want to know if I should plug them both on power supply or not.