that your video card has GDDR5 (Graphic Double Density Ram) has no direct link with the type of DRAM (computer Double Random Access Memory) is used with your computer, now that said, a video card is directly dependent on the type pcie slot your motherboard has to power/utilize it as well as the size of your PSu to be able to power that video card with your motherboard.
so I would ask what make and model are your motherboard , power supply and video card your trying to install ?