CPU performance terminology: The time required for fetching and executing one simple machine instruction is referred to as what?

Introduction / Context:
Measuring processor performance often involves understanding the duration associated with instruction processing. The question asks for the standard term used for one fetch–execute sequence.

Given Data / Assumptions:

• Instruction is 'simple' and typical.
• We consider the combined fetch and execute operations.

Concept / Approach:

The CPU cycle (also called the machine cycle) spans the necessary steps to fetch an instruction from memory and execute it. It differs from a single oscillator clock tick; multiple clock cycles may compose one CPU cycle depending on architecture.

Step-by-Step Solution:

Verification / Alternative check:

Architectures document instruction timing as cycles per instruction (CPI), i.e., number of clock cycles required per CPU cycle for a given instruction mix.

Why Other Options Are Wrong:

• Delay time: generic latency term.
• Real time: refers to time-constrained systems.
• Seek time: storage head movement delay, unrelated to CPU.
• None: incorrect because 'CPU cycle' is correct.

Common Pitfalls:

• Confusing a clock cycle with a CPU/machine cycle; the latter may include several clock ticks.

Final Answer:

CPU cycle.