Question

Which of the following refers to a cache where updates are sent to memory when the cache evicts a block that has been written to?

a) Write-through cache
b) Write-back cache
c) Direct-mapped cache
d) Associative cache

Answer 1

A write-back cache updates the main memory when a cache block is evicted after being written to, in contrast to a write-through cache, which updates the main memory immediately on every write operation.

Step-by-step explanation:

The cache that updates memory when the cache evicts a block that has been written to is called a Write-back cache. In a write-back cache, data is only written to the main memory when it is removed from the cache, which can happen due to the cache becoming full or the data being deemed not likely to be used again soon. This is in contrast to a write-through cache, where data is written to the main memory as well as the cache simultaneously every time a write operation occurs.