endition of a three-dimensional (3D) object, creating the impression of a textured surface. The fill rate is directly related to the frame rate or the frames per second. In order to achieve the best 3D experience, both a high fill rate and a high frames per second are needed. This report will examine the Voodoo5 5500’s frames per second later on.32-bit Z-Buffer/StencilLike many other 3D cards the Voodo5 5500 features 32-bit Z-buffer/stencil. In order to understand Z-Buffering, you first must possess a basic understanding of Z-Sorting. In order for the computer to give the illusion the computer must calculate which objects should appear to be behind other objects. In Z-Sorting the computer’s rendering engine sorts each polygon from back to front based on its theoretical position on the Z-axis. The computer then draws each object from back to front, objects with a closer Z-axis to the camera overlap objects behind them, creating an image of depth. Z-Buffering is a faster alternative to Z-Sorting. A depth value is assigned to ever pixel that makes up the surface of an object. Pixels that are closer to the camera are assigned lower values while pixels that are further away from the camera are assigned higher values. Before the computer draws a new pixel, the pixel’s depth value is compared with the depth values of the other pixels that share the same coordinates (position on the screen). The pixels are only drawn if they have lowest depth value, meaning that they are closer to the camera. Z-Buffering/stencil ensures that unnecessary pixels, (pixels that would be blocked by a pixel of another object) are not drawn. Synchronous dynamic random access memory (SDRAM)The Voodoo5 5500 has 64MB of Synchronous dynamic random access memory (SDRAM) with a clock speed of 166MHz.Synchronous DRAM (SDRAM) is a generic name for various kinds of dynamic random access memory (DRAM) that are synchronized with the clock speed th...
