Motherboards do not have particular support or no support for video card VRam. It is not linked in any manner. As long as the card is compatible with the PCIe slot (and if you have a motherboard with PCIe 1.1 or 2.0 - or basically any modern motherboard) and you have enough of a power supply, you are good to plug anything you wish. What is your budget for the video card? In which country are you going to purchase?