No! That version of the library analogy makes the ratios much too small. CPU to main RAM: actually about 150:1; more like 30:1 in your analogy. Main RAM to HD

No! That version of the library analogy makes the ratios much too small. CPU to main RAM: actually about 150:1; more like 30:1 in your analogy. Main RAM to HD: actually about 200,000:1; more like 120:1 in your analogy. The reason why "the discussion of second/nanosecond" is worth having is precisely that if you just say "very slow" and "a lot of time" then you're likely to think about ratios of the sort in your analogy, when the reality is much much much worse. (Extreme case: HD to CPU registers. Actual ratio: about 30 million to 1. Ratio in your analogy: about 4000 to 1.)