I purchased 2 7970s a couple hours ago, and they'll most likely be here be Thursday. I see that for power it has one 6 pin and one 8 pin port. I'm out of 8 pins and I only have 1 6 to 8 pin adapter. I read somewhere though that 8 pin isn't totally necessary to power a video card and that I could just use 2 6 pins. Is this true? If so, are there any drawbacks to doing this?