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1. RISC vs. CISC

This section considers an important issue of contemporary processor design.

We normally think of instructions as software. However, machine code is physically included in the CPU for it to be able to carry out tasks such as ADD. The machine code within the CPU effectively takes up physical space because underlying them are actual transistors.

So when we look at different processor architecture such as RISC and CISC we need to be aware that additional instructions within the CPU instruction set means more transistors and so more power consumed.