Butterfly network

This form of multistage interconnection network topology can be used to connect different nodes in a multiprocessor system.

[1] The network derives its name from connections between nodes in two adjacent ranks (as shown in figure 1), which resembles a butterfly.

Therefore, the actual message transmitted from processor 5 is: Upon reaching a switching node, one of the two output links is selected based on the most significant bit of the destination address.

Subsequently, this bit is removed from the destination address in the packet transmitted through the selected link.

The prominent ones relevant in designing large-scale multi-processor systems are summarized below and an explanation of how they are calculated for a butterfly network with 8 processor nodes as shown in figure 1 is provided.

Relevant parameters are compiled in the table[citation needed] (‘p’ represents the number of processor nodes).

The decision is made based on factors like the number of processor nodes in the system, bandwidth-latency requirements, cost and scalability.