i have asus p5 q pl am mother board
-c2d 2.93 ghz
-2gb ram kingston
-500 gb hd
-32 inch lcd sansui
i want to plug 9800gt ddr2 for my motherboard will support
Assuming you have the PCIe socket on your motherboard then yes. You can run a DDR3 or DDR5 card on your board. You don't need to run DDR2 like your motherboard. The RAMs are kept separate, so no need to worry.