Memory Hierarchy Questions and Answers

Answer: B

Statements (i) and (iii) are true, so the answer is (B).

A cache holds recently used words, and a small loop uses the same instructions again and again, so it runs from the cache and gains most from it (i). Interleaved memory spreads consecutive addresses across several memory banks, which can be read at the same time, so long runs of sequential code are fetched faster (iii). Statements (ii) and (iv) swap the two, and are not true, because a small loop gains little from interleaving and long sequential code is not served well by a small cache.

Answer: D

The key is "None of these". Serial access memories, such as shift registers and tapes, are useful when information is processed in order and every stored word is handled in the same way. They are not suited to uses where data is only numbers (any memory can hold numbers), nor where short access time is needed, since reaching a word means stepping through the earlier ones, nor where each word is handled differently.

Each of the other three options therefore fails, leaving the fourth.