Having a crosshair motherboard, with two video cards(xfx 8600) that are in pci express x 16
slots, can they (veido cards)be replaced with newer cards like
PCI Express 2.0 x16.
To answer your question better. Newer Graphic cards will work if they are PCI Express 16 slots. But, they will not work at their full potential. Your motherboard may only be using PCI Express 1.0 @ 16x speed. But Newer Graphic cards will work if they are the same slot compatibility.