Power Cable that comes with Decklink 4K Extreme 12G

Hi all. I read the installation instructions page for the DL 4K Extreme 12G but couldn't find what I was looking for. It looks like the DL 4K Extreme 12G PCIe card has a connector for an internal power cable that would connect to a motherboard, much like the one that connect from my ATI 5770 to my Mac Pro motherboard. Is it suggested to connect this? Or is this only for PC systems?

Thanks,
Mark