How fast is messaging?
Depends on several factors
- Physical communication link
- Software protocol overhead
- Number of copies of data that must be made to pass the message
Obviously, the faster the better
- All delays must be addressed - does not do any good to have a 1 Gb/s link between processors if the software overhead of sending a message is in the microseconds
- Message Latency on the order of hundreds of nanoseconds has been achieved (Table 17.2).