Moore’s Law has fundamentally changed the data center. Plentiful processing power has driven the success of technologies like high performance computing, highly scaled database environments and of course virtualization and cloud computing. But to take advantage of all that CPU power requires that the data to be accessed be readily accessible. Flash based solid state disk (SSD) has been a good start, and 3D NAND is the logical next step towards making high performance storage affordable enough to delivering on the potential of abundant processing power.
What is 3D NAND?
Today NAND flash device architectures are “planar”, meaning they’re one-dimensional, storing more data by enlarging their ‘footprint’ (the X and Y axes) or by increasing density. But as lithographies continue to shrink in size and in cost, squeezing more bits into each NAND flash cell becomes more challenging, to the point that manufacturers believe we’re approaching the practical limit.
Companies like Intel are taking a new direction, literally, by going vertical, to develop the next generation of flash technology. By stacking NAND flash cells they’re expanding in the “Z” direction, creating a 3D NAND offering that can continue to decrease the price per bit. Think of 3D NAND as an apartment building and 2D as a single family house. Both take the same amount of real estate (X-Y dimension), but the apartment is more efficient with that space because it can expand upwards.
3D NAND vendors will also back off a bit on the lithography being used. Lithography is the physical dimensions of the NAND. As it scales down and becomes more dense it also becomes more cost effective. It also becomes harder to correct errors.
While making the NAND less dense will make them a little less efficient in their horizontal space consumption, the vertical stack will more than make up for it. Backing off on the lithography will produce higher yields, better durability, better power utilization (more capacity per watt) and potentially higher write speeds.
The Enterprise and 3D NAND
3D NAND is not some distant future concept. Intel for example has committed to delivering production 3D NAND later this year. In fact at their analyst day event, the presentation was served up from 3D NAND storage. The key advantage of 3D NAND for the enterprise is a lower cost per bit. Intel for example expects to deliver a 10TB SSD sometime in 2016.
Expect to see MLC and TLC versions of 3D NAND in 2015. The durability of 3D NAND should be about the same as their 2D counterparts. Storage Switzerland expects that data centers will see most major all-flash and hybrid flash array vendors delivering 3D NAND based systems as early as 2016. The key impact will be the size of these systems. If the industry stays with current form factors the capacities per system could increase by 5X or more.
The other alternative is to go with custom form factors that deliver similar capacities to today’s systems. Imagine a 2U system that has all the CPU power required to drive storage system software, 25 to 50TBs of capacity all while delivering 250k to 500k IOPS. If these form factors become a reality the data center is going to shrink dramatically in 2016 and become far more power efficient.