
1.4 Concluding Remarks 63
frequency or volume of communication increase, greater stress is placed on the com-
munication architecture.
The overlap is the portion of the communication operation that is performed con-
currently with other useful work, including computation or other communication.
This reduction of the effective cost is possible because much of the communication
time involves work done by components of the system other than the processor,
such as the communication assist, the bus, the network, or the remote processor or
memory. Overlapping communication with other work is a form of small-scale par-
allelism, as is the instruction-leve ...