Okay, my PSU (http://www.newegg.com/Product/Product.aspx?Item=N82E168...) arrived today and while I was looking at it I noticed that it only has two 6 pin PCI connector slots. I was planning on having 2 6870s in crossfire but they require two 6 pin PCI connectors each. So I'm wondering if there is any way for me to still have 2 6870s in crossfire other than buying a new PSU. I'm just fine with having just one 6870 but would like to have the option to have 2 in crossfire. Thank you for your time.
First, it's something you should checked before you bought the PSU...
second, many cards come with an adapter in case the PSU does not have enough 6-pin connections. MSI's HD 6870 comes with two such adapters. click the link below and select the right most tiny preview picture which show all included accessories.
Yes, you can. Bestbuy will probably have them, but it may be cheaper to buy on line. I say "may" 'cause the shipping charge might be outrageous. I recall seeing a SATA cable being sold somewhere for $3, but the standard shipping charge was $7.
You can also check Radio Shack if there's one near you.
Also, my psu has four molex 4 pin slots. Would it matter if I used them all to power a gpu? Would I need them for other things?
Molex is typically only used for older floppy and CD-ROM drives, so no it probably won't matter.
Jaguar: Shipping usually is pretty ridiculous for small items like that. I needed to buy a couple molex adapters last year. Online the prices were around 4 bucks and then tack on at least that much for shipping. It was easier to just go to Best Buy and get them for the 6 or 7 bucks that they want for them. Radioshack might work too.