Question about cross fire/SLI

Ok, I have a x58 pro motherboard that says it runs Crossfire. Mind you ths is a MSI Mobo.. anyways I want the MSI gtx 560, Nvidia.. Now im confused. why it wouldnt let me use SLI or would it?

Thanks

Iv always used Nvidia, but recently I was going to run two 9800gt's SLI but it wasnt working, then looked into my MOBO and noticed it says Crossfire. ( im afraid to go to ATI! :(

"Once we had finished overclocking we followed a hint from MSI and installed the BIOS from the X58 Pro SLI motherboard. We downloaded BIOS version 8.0, booted with a USB key and installed the BIOS without any trouble. The result was that our X58 Pro suddenly gained the ability to run SLI as well as CrossFire so we plugged in a pair of GeForce GTX 280 graphics cards and ran a quick set of benchmarks which delivered impressive results. "

Got it :)