text: i want to use 2  pci express graphic cards, is there any compalibility should i consider? i have one geforce 6600gt pci express card and a mainboard with pci express slot, and i want to buy another pci express graphic card, do i need to buy the same type or i can buy a higher version of graphic card? it has to be the same chip on both video cards .... the manufacturer shouldnt matter, be it evga, xfx, bfg but make sure they are both 6600gt