Computing System CS Thinking Example 2
Follow the full solution, then compare it with the other examples linked below.
Example 2
mediumDescribe the fetch-decode-execute cycle that the CPU performs. Why is clock speed relevant?
Solution
- 1 Step 1: Fetch: the CPU retrieves the next instruction from memory (RAM) using the program counter.
- 2 Step 2: Decode: the CPU interprets the instruction to determine what operation to perform and what data to use.
- 3 Step 3: Execute: the CPU carries out the instruction (e.g., add two numbers, store a result, compare values). Clock speed (measured in GHz) determines how many of these cycles occur per second — higher clock speed means more instructions processed per second.
Answer
Fetch (get instruction from memory) → Decode (interpret it) → Execute (carry it out). Clock speed determines how many cycles per second.
The fetch-decode-execute cycle is the fundamental operation of every CPU. Every program, from a simple calculator to a complex game, is ultimately executed through billions of these cycles per second.
About Computing System
A complete, functioning combination of hardware, software, and data that processes information and performs tasks. Computing systems follow the input-process-output model: they receive data, process it according to programmed instructions, and produce results.
Learn more about Computing System →More Computing System Examples
Example 1 easy
Name the three main components of a computer system and describe what each does.
Example 3 mediumExplain why a computer with a fast CPU but very little RAM might still perform poorly. What would th
Example 4 hardCompare the computing systems in a smartphone, a laptop, and a data centre server. How do they diffe