Quote Originally Posted by Raja@ASUS View Post
Not sure, I just know that dissimilar/custom BIOSes can cause issues engaging SLI.

-Raja
Fixed !

I flashed first bios with 1485 and second with 1409 .
Booted win7 with 1485 and enabled SLI . Then shut down , change bios to 2nd and boot win7 again .

Now it's working properly .