this board has 4 PCI16 slots what video cards do u use for a NVIDIA SLI Quad PCI-E graphics set up?

Question's not really that clear, but I think that you're asking what video cards to use to get SLI?  Or maybe which slots?

1st answer: Two Identical (Same Company, Same Model) video cards will do the trick.

2nd answer: The motherboard has 4 PCI16 slots, but only two run at x16, consult the manual to find which ones and use those.  They're usually the top and middle (spaced for SLI connector).

As of now, you can't use 4 PCIe x16 slots to run a Quad-SLI setup.

i thought so thx 

the slots are set up in sets, connoted by color....black and blue..  Use the two blue or two black slides for your matched cards.  We are using the nforce 7950 and they work great!