Abstract: A graphics system and a memory device for three-dimensional (3D) graphics acceleration, and a method for 3D graphics processing, are provided. In a memory device in a graphics system for 3D graphics processing, a memory structure includes a first memory area allocated to a texture buffer for storing texture data, and a second memory area allocated to a frame buffer for storing frame data in pixels. A comparator controls the memory structure to operate as the texture buffer if an input address to the memory structure indicates the first memory area and controls the memory structure to operate as the frame buffer if the input address indicates the second memory area. If the memory structure operates as the frame buffer, an ALU performs depth comparison or alpha-blending on input frame data and frame data read from the frame buffer.