Can PCI-E power connector used as EATX12V?

Hi guys,

Here's my situation, I'm building my first pc, and my power supply came with a 12V connector with only 4pins when my mobo as an EATX12V support of 8pins (I know I can still use only 4pins but I want to overclock my cpu). Also it came with a PCI-E power connect that has 6pins + 2pins! My graphics card came with an adapter where I can connect the 6pin to 2 molex connectors. So if I use that, could I use the PCI-E 8pins for my EATX12V?

Thanks!