Is it wrong to say that this is mostly just two drives stacked on top of each other, inside the same enclosure? If so I'm not quite seeing the benefit over RAID 0.
I was expecting multi-actuator to mean two sets of heads sharing the same platters. Now THAT would be a fun engineering challenge.
As I understand it: By itself, it's theoretically about the same as two (non-RAID) hard drives. They show up as separate LUNs [or similar]. Like two standalone drives, these can be used independently or made into RAID 0 or lots of other things.
But compared to using two drives, these have half as many spindles, half as many spindle motors, and half as many spindle bearings.
That's not a small reduction in complexity, and reductions in complexity tend to improve MTBF.
Furthermore, they can theoretically use about half of the physical volume. And half the external connections and cabling.
And (maybe, some day) this can all combine to reduce the overall cost of adding a headstack (or a thousand of them) in some applications where that is a useful thing.
I was expecting multi-actuator to mean two sets of heads sharing the same platters. Now THAT would be a fun engineering challenge.