We simulated only two cases, which are 4KB and 8KB managing granularity, and
determined to use 4KB based on write-back traffic and hit rate. We don’t consider
sizes greater than 8KB because one fetch-block from the AFBB can be divided into a
set of sub-blocks to check reusability. Thus, only recently accessed sub-blocks can be
collected to move into the next level DDCB buffer. This is because the DDCB buffer
can only receive evicted data from the AFBB, and only reusable sub-blocks need to be
maintained for optimal reusability.