Their considerations that reduce latency...."inventions in caching, data compression and data tiering" that reduce latency." or three distinct details.

With the noted inventions caching and data tiering......the consideration is I/O and not utilizing the flash as a cache.

That leaves three possibilities....the author is misinformed and there is something wrong with the write up, someone is purposely throwing out the confusion, or they are doing both.

FWIW

doni