That board only has two pci-e slots which can be used with video cards.
lol, tell that to my four 5830s then

If you are using risers on pci-e 1x slots for video cards, then you're killing the bandwidth. Might as well chop the card in half while you're at it.
getting 260 Mhash/sec out of each one, with 875 core clock and 900 mem clock, running at 59-64 C. ::shrug::