So far, we've looked at some complete communication networks where each processor can communicate with the others directly, without the need for any switch. This arrangement serves well when there is a small number of processors but can become a real pain if the number of processors needs to be increased. There are various other performance topologies available that can be used. There are two important aspects while measuring the performance of a graph in a topology:
- The diameter of the graph: The longest path between the nodes.
- Bisection bandwidth: The bandwidth across the smallest cut that divides the network into two equal halves. This is important for networks where each processor needs to communicate with the others.
The following are examples of some network topologies.