Run on fast SSD, USB3 or internal.
Back up on and stream from far cheaper HD.
Forget the evolutionary freak which is the "fusion" drive. It's days are numbered. (Except at Apple, which will be selling a 1TB 5krpm spinner, with a 128 GB fused SSD in 2028, on its new Mac Mini, which is almost certainly coming).
W00t, Fusion is "evolutionary freak"?
Well then, what isn't?
Are SANs that use 4 different speed storage also freaks?
Archive libraries that use automatic archiving with 6 different media?
For those, who don't care about cost-effectiveness of their storage, Fusion is "crap" and "complicated" ("OMG, my computer has TWO different memory: RAM and storage!")
But for those who do, Fusion is best that Apple has put to a mac in this decade.
Most mac users won't ever even notice the speed difference between fusion and plain ssd, let alone suffer from it.
Just bought a 2012 mini, 1TB fusion for it will cost less than $100, 1TB ssd from Apple (soldered, will brick the whole mac when it dies) costs about $1k overall! (BTO 500GB hdd -> 1TB fusion = $250, 1TB fusion -> 1TB ssd = $600)
Just wondering why is it so cool to waste ca. $900 for nothing?
Showing that you are wealthy is so much effective with cars.
Saddest thing, IMHO, is that Apple's major decisions about tech has long been to maximize profits, regardless of technological optimization.
It started with optical disks; "Rip, Mix and Burn" was a revolution that stopped, when Apple wanted users to buy their content from iTunes. ODD slot in macs can't be used as modular slot (for extra battery or storage), because of unibody and once again "complexity". Modularity would mean expandability, which is bad, so let's just solder and glue.
Fusion drive is bad, because with it, Apple can't charge 2x prices from ssd, which isn't needed anyway.
So fusion is not allowed in macbooks ever (I have fusion in my 17" mbp, another reason why my next macbook will not be as good) and Apple will kick it away from desktops as soon as possible.
Macs are overall so irrelevant to Apple now, that I don't get why they keep hinder us hobbyist and pro builders with not letting osx/macos officially out for licensing. What is that they are afraid to loose? Price-experience ratio with macs isn't in their DNA anyway...
(Anybody ever noticed how someting is or isn't "in their DNA"? And then it suddenly reaches the reality distortion field?)