My ga-f2a88x-up4 motherboard has an 12v atx 8 pin and my power supply (antec earthwatts 500w) has 2x 4 pins but one has a sticker in it saying "use for single cpu use" what does that mean? And csn I just use 4 pins in the atx 12v 8 pin slot or does it have to be all 8?