The following is a quote from Gene Amdahl, in 1967:
"For over a decade prophets have voiced the contention that the organization of a single computer has reached its limits and that truly significantly advances can be made only by interconnection of a multiplicity of computers in such a manner as to permit cooperative solution... The nature of this overhead (in parallelism) appears to be sequential so that it is unlikely to be amenable to parallel processing techniques. Overhead alone would then place an upper limit on throughput of five to seven times the sequential processing rate, even if the housekeeping were done in a separate processor... At any point in time it is difficult to foresee how the previous bottlenecks in a ...