Which of the following statements are true?
A. In the write-through policy, only the cache is updated
B. In the write-back policy, both cache and main memory are updated
C. Cache coherence problems exist in multiprocessors with private caches because of the need to share writable data
D. Cache coherence problem can be solved by means of hardware-only scheme
🎥 Video solution / Text Solution of this question is given below:
A is false — In the write-through policy, both cache and main memory are updated simultaneously.
B is true — In write-back policy, data is first written to cache and later updated in main memory when replaced.
C is true — Cache coherence arises in multiprocessors with private caches that share writable data.
D is false — Cache coherence solutions usually need both hardware and software support, not hardware-only.