I'm reading conflicting information. Some reviews are saying that it's only a 5% performance loss by having an x16/x4 PCI-E setup, whereas other sites are saying that it's a much greater performance penalty. I'm wondering if I would be much better off with an x8/x8 board. I'm going to go with Crossfire or SLI eventually once a hot enough deal crops up on a card. Is it worth upgrading my x16/x4 board or should I just sit tight and go with a fast single card?