The only significant performance difference between superpipelined machines and superscalar
machines is that in general only the superscalar machine can have class conflicts. (A
superpipelined machine in which some functional units were not pipelined would also have class conflicts, but it is relatively easy to pipeline functional units.) Class conflicts can reduce the
performance of the superscalar machine relative to the superpipelined machine of similar degree.
A more important difference between superscalar and superpipelined machines, however, is their
implementation cost.