I have built around 13 machines but this is the first with these cards. I've never seen this before but they have a 8+6 power connection. Do I really need to connect the extra 6? Apparently this is so the card can pull 350w if needed.

Will it run on the the 8 pin (6+2) connection? The evga 1300 watt power supplies do not have sufficient cables (or power slots) to power 6 of these.

Advice?