The performance of highly integrated, single-chip CMOS microprocessors is steadily increasing.
In fact, these fast processors are now the best building blocks for multiprocessors.
So, to get performance better than that provided by the fastest single processor, we should figure out how to hook those processors together rather than rely on exotic circuit technologies and unconventional machine organizations.
Given a serial program, it is usually not easy to transform it into an effective parallel program.
The measure of whether a parallel program is effective is how much better it performs than the serial version. This is usually measured by speedup.
Given a fixed problem, the speedup is measured by—