Review of Memory Hierarchy - Computer Architecture: A Quantitative Approach - page 581

As this example shows, there may be less confusion with multilevel caches
when calculating using misses per instruction versus miss rates.
Note that these formulas are for combined reads and writes, assuming a write-back first
level cache. Obviously, a write-through first-level cache will send all writes to the second level,
not just the misses, and a write buffer might be used.
Figures B.14 and B.15 show how miss rates and relative execution time change with the size
of a second-level cache for one design. From these figures we can gain two insights. The first is
that the global cache miss rate is very similar to the single cache miss rate of the second-level
cache, provided that the second-level cache is much larger than the first-level cache. Hence,
our intuition and knowledge about the first-level caches apply. The second insight is that the
local cache miss rate is not a good measure of secondary caches; it is a function of the miss rate
of the first-level cache, and hence can vary by changing the first-level cache. Thus, the global
cache miss rate should be used when evaluating second-level caches.