Thanks, Artie.
I may be beginning to understand and appreciate the nuances here, but only with respect to SSDs (I still don't see the problem with spinning drives).
I don't doubt the counsel is sound, it's only that I would be uncomfortable explaining all this to others. And to me, that is a clue is clue that my understanding ain't really what it ought to be…
As far as Time Machine or OS X (and the same is true for Windows, Ubuntu, Unix,
etc.) is concerned they see exactly the same
logical drive regardless of whether the drive is a rotating media HD or an SSD. The
intelligence/firmware in the drive itself is specifically designed to make the
physical layout of data on the drive as well as the actual storage media invisible to the operating system and therefore to applications. That is the principal function of the IDE/PATA/SATA interface.
The OS views Fusion Drives and even multi-drive RAID arrays as having the same
logical structure as a single HD or SSD but there is an additional layer of abstraction either in software or hardware required to make that happen.
