grapchics card

Hey guys! My first question here. I bought a new graphic card, and come to find out it requires an 8 pin input from the power source, and my last graphics card was 6 pin. So, I did a little research, and found out I can use an adapter with 2 x 6 pin heads (input), that comes to an 8...

So I have multiple PSU's with an XFX Rx580 which needs a 8 pin power connector however in the box it includes a converter to two 6 pin power connectors. The PSU I have in my computer only has one 6 pin connector and I have another PSU with another 6 pin connector. I was wondering if I could plug...