Review of Memory Hierarchy - Computer Architecture: A Quantitative Approach - page 575

FIGURE B.11 Actual miss rate versus block size for the five different-
sized caches in Figure B.10 . Note that for a 4 KB cache, 256-byte blocks
have a higher miss rate than 32-byte blocks. In this example, the cache would
have to be 256 KB in order for a 256-byte block to decrease misses.
Answer
If we assume the hit time is 1 clock cycle independent of block size, then the
access time for a 16-byte block in a 4 KB cache is
and for a 256-byte block in a 256 KB cache the average memory access time is
Figure B.12 shows the average memory access time for all block and cache
sizes between those two extremes. The boldfaced entries show the fastest block
size for a given cache size: 32 bytes for 4 KB and 64 bytes for the larger caches.
These sizes are, in fact, popular block sizes for processor caches today.