are different. The mobo with the PCI Express 16 slot MUST use a PCI E card [unless it has onboard video LOL].
probably a really simple question but on well. if i was looking at a mother board that had an x-16 port on it but was also thinking about an agp 8x card that wouldnt work correct? or would it? just noticed that the board i was looking into getting only supports PCI and the 6800gt only seems to come in 8x AGP. i assume it has to be pick either the board or the card right?