PCI Express 1.0 not compatible with 2.0 spec
 

With Asus latests P35 gaming boards, the Blitz Extreme and Blitz Formula, which are using an IDT chip to give you two x8 PCI Express slots instead of the normal x16 and x4 configuration of the P35 chipset, a problem has occured on the Asus FAQ. It seems that the second slot is PCI Express 1.0/1.0a only and according to Asus, this older PCI Express standard isn't compatible with PCI Express 2.0.

http://www.fudzilla.com/index.php?op...99&Ite mid=34