If cost per capacity were your only concern, you would still be using tape. You can get LTO-6 for $12/TB, but HDDs start at more like $25/TB, and SSDs are more

If cost per capacity were your only concern, you would still be using tape. You can get LTO-6 for $12/TB, but HDDs start at more like $25/TB, and SSDs are more like $250/TB. SSDs keep dropping in price, but without a major breakthrough, the crossover probably won't happen before 2020. 2020 is far enough away (how many generations of semiconductor fabrication is that?) that most people are hesitant to make this kind of prediction. So the best answer is, "Who knows? Probably not for a few years, at least." We'll continue to see hybrid fleets for a while yet. Maybe, in the meantime, the SSDs will be cheap enough that you don't need something cheaper.