If you're just counting the flash chips on circuit boards, I would think that you could fit many more SD innards and wire them together with some type of controller in this space. I don't doubt however that given the use-case, it has some room allocated for chips going bad, heat dissipation, etc inside. If they could have made a 20TB drive instead for the enterprise market in this form factor, they would have.

Yep, that's exactly what I was asking. Remember also that both solutions have to use the SAS connector to interface with the main board. It's a little disingenuous to say that Samsung could have glued a bunch of SD cards together because it's not really comparing apples to apples.