He's talking about what type of VRAM the graphics card has, not the type of system memory you are using. What is the exact model number of your graphics card?
Not that it really matters, since you already have the card anyway. Regardless, both DDR3 and DDR5 versions of all 1000 series graphics cards will be compatible with the motherboard you inquired about. Or any other motherboard made in the last four to six years, at least. Maybe longer.