Practice question · Select all that apply
Select every statement that the bottleneck principle actually supports.
Hints
- Two of the options make absolute claims that the lesson explicitly contradicts.
- Recall the order of magnitude separating a register access from a disk access.
Show the answer
- A. You should measure where time is spent before optimising
- B. Doubling CPU speed on an I/O-bound task barely helps
- D. Speeding up a stage that is not the bottleneck gives little overall gain
Why
The principle says overall time is governed by the slowest stage, so improvements elsewhere barely register and measuring must come first. The layers differ by factors of millions, not a small factor, and the bottleneck is very often I/O or memory rather than the CPU, which is why option 5 inverts the lesson.
Practise Integrated Computer-System Reasoning
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