Parallel rendering
The Rendering of graphics requires high computational resources for complex objects like medical visualization, iso-surface generation or some of the CAD applications. The traditional methods like Ray-Casting, 3D Textures etc that are used for such applications work terribly slow in simple machines.
To improve upon the performance of such applications Parallel Rendering can be used. Parallel Rendering is dividing the work to be done and processing it in parallel. For example, if we have a ray-casting application, we would be sending rays one by one to all the pixels in the view frustum. Instead we can divide the whole frustum into some x number of parts and then run that many threads or processes to send rays in parallel to those x tiles. We can use a cluster of machines to do such thing and then composite the results. This is parallel rendering.
Parallel Rendering can be used in graphics intensive applications to visualize the data more efficiently by adding some resources like more machines etc.
There is an open source software chromium (http://chromium.sourceforge.net) that provides parallel rendering mechanism for existing applications.