Winn L. Rosch Hardware Bible, Sixth Edition

Performance-Enhancing Architectures

Functionally, the first microprocessors operated a lot like meat grinders. You put something in such as meat scraps, turned a crank, and something new and wonderful came out—a sausage. Microprocessors started with data and instructions and yielded answers, but operationally they were as simple and direct as turning a crank. Every operation carried out by the microprocessor clicked with a turn of the crank—one clock cycle, one operation.

Such a design is straightforward and almost elegant. But its wonderful simplicity imposes a heavy constraint. The computer's clock becomes an unforgiving jailor, locking up the performance of the microprocessor. A chip with this turn-the-crank design is locked to the clock speed ...