That's the definition of a write-through cache, not caching in general. http://en.wikipedia.org/wiki/Cache_(computing)#Writing_policies http://en.wikipedia.org/

That's the definition of a write-through cache, not caching in general. http://en.wikipedia.org/wiki/Cache_(computing)#Writing_policies http://en.wikipedia.org/wiki/Cache_(computing)#Writing_polic... Also, is it really true that data is always read from the SSD? So if a block is requested that only exists on the hard drive, the data must be copied from the hard drive to the SSD, then read from the SSD--rather than simply reading the data from the hard drive?