Ever since solid-state drives (SSDs) hit the consumer market, they’ve offered significantly better performance than traditional hard drives (HDDs), but at a significantly higher price. The gap between SSDs and HDDs in terms of capacity and price has decreased dramatically, but hard drives still have an edge over SSDs in price per GB. Samsung wants to slash the existing gap by 2020 and offer a 512GB SDD for the same price as a 1TB HDD today.
Right now, SSDs generally cost between 20-50 cents/GB depending on capacity, NAND type, and form factor. Conventional 1TB hard drives are down to about 4 cents per GB, though this also varies depending on make and model. 1TB drives aren’t always the most cost-effective option — as manufacturers move to higher platter densities, it wouldn’t surprise us to see 2TB – 4TB drives offering higher capacities at a lower price per GB. Delivering a 512GB SSD at a $40 price means a significant cost reduction between now and 2020; Samsung needs to cut the current price of NAND storage by roughly two-thirds to hit its target.
The key to doing this will be scaling up Samsung’s 3D NAND production and layer density. As we’ve previously discussed, 3D NAND (or V-NAND) stands the NAND array on edge relative to conventional 2D planar production. This allows for much denser memory chips, as shown below:
These density figures are only for Samsung’s first-generation 3D NAND.
Conventional planar NAND shrank the space between the cells with each generation. V-NAND focuses on scaling upwards by adding new layers rather than taking up less space per layer. While this currently offers better scaling characteristics and longevity than 2D NAND, it’s by no means easy. Samsung initially debuted 32-layer NAND and announced 48-layer NAND last year, but took nearly a year to bring it into wide production. The company will need to hit 64 or 96-layers to hit its intended cost targets, and it might need a die shrink as well. To date, all of Samsung’s 3D NAND has been produced on a 40nm process. Cutting existing prices by a further two-thirds will probably require an aggressive technology rollout.
Hopefully, cost reductions this significant will also spur adoption by OEMs. SSDs are much more common than they used to be, though the majority of PCs still ship with spinning media. Some manufacturers use drive caching to offer a performance boost while still cutting costs. But many don’t, or only offer SSDs or cache drives on the most expensive models. This makes a certain degree of sense given the low ASPs of your average laptop or desktop PC, but it’s still unfortunate. Hopefully in the next few years, we’ll see SSDs shipping as standard more often, particularly as rising capacities make it easier for people to rely on a single drive for storage. High-end drives are still setting capacity records, but the extreme cost of these solutions makes them far more expensive than anything in conventional magnetic disks.