^ A reference card refers to the originally designed board from the chip set designer (ATI/Nvidia) for each generation of product. The third party manufacturers can then choose to skip the expense of the R&D process and simply use the reference/original card or come up with a design of their own.
IC, so reference cards are normally sold by the manufacturer in this case ATI/NVIDIA. The rest in the market are non reference cards? How do we know if we have a reference card?