Learn: RISC vs. CISC Architecture

Welcome!You've already learned about the Fetch-Decode-Execute cycle and CPU components. Today, we'll explore how different processor architectures, RISC and CISC, affect performance and design.

What is Processor Architecture?Processor architecture refers to the design and structure of a CPU. It determines how the CPU processes instructions, stores data, and interacts with memory. Two main architectures are RISC (Reduced Instruction Set Computer) and CISC (Complex Instruction Set Computer).

What is RISC?RISC stands for Reduced Instruction Set Computer. It uses a smaller set of simple instructions that can be executed quickly. RISC processors emphasise efficiency by using instructions that take fewer cycles to execute.

What is CISC?CISC stands for Complex Instruction Set Computer. It uses a larger set of instructions, including more complex ones, which can accomplish more tasks in a single instruction. This can reduce the number of instructions needed overall but often takes more cycles per instruction.

Key Differences Between RISC and CISCRISC uses simple instructions that execute quickly, while CISC uses complex instructions that can accomplish more but take longer to execute. RISC processors are often used in applications requiring high efficiency, like mobile devices, while CISC is common in general-purpose computing like desktops.

Why Choose One Architecture Over the Other?The choice depends on the application. For example, RISC is ideal for tasks requiring speed and efficiency, like mobile and embedded systems. CISC, with its more complex instruction set, works well for general-purpose computing where flexibility is important.

Review Time!Great work! You've learned about RISC, CISC, and their differences. Now let's test your understanding with a few final questions.