You are quite correct about the Fusion drives, they are a 64gb (maybe even less? They downgraded them recently, my older one is 128GB) SSD and a normal 1TB spinner... its possible to split them (which I ended up doing for a bit).
It's also possible to make your own in terminal. Takes about ten minutes. Why anyone would pay for one is beyond me.
If you were running OSX on that HP you could combine those two drives into a fusion drive in minutes.
Aye, easiest way to get 2 drives in a Mac though, I had an extra drive fitted into a Mini once but wouldn't be keen on cracking open an iMac to put another drive in to create a Fusion...
It's also possible to make your own in terminal. Takes about ten minutes. Why anyone would pay for one is beyond me.
If you were running OSX on that HP you could combine those two drives into a fusion drive in minutes.