Hey guys, I just had a quick question about crossfire with my motherboard. I have a Foxconn A7DA-S, which isn't an amazing board by any means, but it's still pretty nice and gets the job done. Anyway, I was thinking about getting a Radeon HD 5870 once I save up some money and the price drops when Nvidia's cards come out.

In the motherboard manual it says that when both PCI-E 2.0 X16 slots are occupied that both slots only operate at X8 speed. If I were to buy another 5870 in the future, plug it into my board, and put the cards in Crossfire, would I see a significant improvement in performance?