Blah, seems a long way from usefulness. I guess it comes down to areal density vs hard drives. If we want a miracle data storage technology for backup, it woul

Blah, seems a long way from usefulness. I guess it comes down to areal density vs hard drives. If we want a miracle data storage technology for backup, it would fundamentally need to either be much better in bits/in^2 or a lot of layers. My google math says 50nm x 50nm x 4 bits is right at a terabit/sq inch. HDDs are around 1.34 terabit per sq inch. They have more tricks, but it does seem that it'll be harder to move forward. I guess a bluray was 12.6 gigabits/sq in, and could at least be stacked to four layers with dual-sided dual-layer, about 50 gigabits/sq inch. I think theoretically optical media is very durable, but I still remember the organic dyes in consumer DVD-Rs fading pretty quickly. Hm, SSDs are passing hard drives in areal density. A 2016 article says they hit 1.6 terabits/sq in. I think SSD makers have closed in on over 64 layers/stacks, and they are at 4bits/cell now. Oh jeez, are they doing 6 ad 8 per cell too? Yeesh that seems very unreliable. SSDs can't shrink their cells because it reduces durability of the cell, so their path forward is more stacking or just stacking chips on chips as fabs making them drop the costs. SSDs also fail at long-term storage. So maybe the mythical 500TB cube of data will still have to be optical/holographic.