A Level Computer Science OCR Practice Exam

Which characteristic describes RISC architectures?

1. It has a complex hardware design

2. It specializes in executing complex instructions

3. It focuses on executing a limited number of simple instructions

4. It is optimized for desktop environments

The correct answer is: It focuses on executing a limited number of simple instructions

RISC architectures, which stand for Reduced Instruction Set Computer, are designed with the principle of simplifying the instruction set to improve performance. The focus on executing a limited number of simple instructions allows for faster processing as each instruction can be executed in a single clock cycle, minimizing the time spent on instruction decoding. This simplicity supports efficient pipelining, where multiple instruction phases can be overlapped, further enhancing the throughput of the CPU. In contrast, other options highlight characteristics that are not aligned with RISC principles. Complex hardware design, for example, is more associated with CISC (Complex Instruction Set Computer) architectures, which contain a broader and more intricate set of instructions. Similarly, a focus on executing complex instructions and optimization for desktop environments are not defining traits of RISC architectures, which are more often utilized in environments requiring efficient and consistent instruction execution, such as embedded systems and mobile devices.