Render Output unit
Encyclopedia
The Render Output Unit, often abbreviated as "ROP", and sometimes called (perhaps more properly) Raster Operations Pipeline, is one of the final steps in the rendering process of modern 3D accelerator boards. The pixel pipelines take pixel
and texel
information and process it, via specific matrix and vector operations, into a final pixel or depth value. The ROPs perform the transactions between the relevant buffer
s in the local memory
- this includes writing or reading values, as well as blending them together.
Historically the number of ROPs, TMUs
, and pixel shaders have been equal. However, as of 2004, several GPUs have decoupled these areas to allow optimum transistor allocation for application workload and available memory performance. As the trend continues, it is expected that graphics processors will continue to decouple the various parts of their architectures to enhance their adaptability to future graphics applications. This design also allows chip makers to build a modular line-up, where the top-end GPU are essentially using the same logic as the low-end products.
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
and texel
Texel (graphics)
A texel, or texture element is the fundamental unit of texture space, used in computer graphics. Textures are represented by arrays of texels, just as pictures are represented by arrays of pixels....
information and process it, via specific matrix and vector operations, into a final pixel or depth value. The ROPs perform the transactions between the relevant buffer
Buffer (computer science)
In computer science, a buffer is a region of a physical memory storage used to temporarily hold data while it is being moved from one place to another. Typically, the data is stored in a buffer as it is retrieved from an input device or just before it is sent to an output device...
s in the local memory
Ram
-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
- this includes writing or reading values, as well as blending them together.
Historically the number of ROPs, TMUs
Texture mapping unit
A texture mapping unit is a component in modern graphics processing units , historically it is a separate physical processor. A TMU is able to rotate and resize a bitmap to be placed onto an arbitrary plane of a given 3D object as a texture...
, and pixel shaders have been equal. However, as of 2004, several GPUs have decoupled these areas to allow optimum transistor allocation for application workload and available memory performance. As the trend continues, it is expected that graphics processors will continue to decouple the various parts of their architectures to enhance their adaptability to future graphics applications. This design also allows chip makers to build a modular line-up, where the top-end GPU are essentially using the same logic as the low-end products.
See also
- Graphics pipelineGraphics pipelineIn 3D computer graphics, the terms graphics pipeline or rendering pipeline most commonly refers to the current state of the art method of rasterization-based rendering as supported by commodity graphics hardware. The graphics pipeline typically accepts some representation of a three-dimensional...
- Rendering (computer graphics)Rendering (computer graphics)Rendering is the process of generating an image from a model , by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene...