SSD-watchers have expressed some concern over the last few years that SSDs cannot be manufactured using advanced NAND flash process geometries. This is because these parts have lower endurance and a larger number of bit errors than NAND made using less-advanced processes – the tighter the process, the shorter the flash’s life, and the more errors it will have.
Fortunately these concerns seem to be overblown: Within the past two weeks there have been three important announcements involving 19-20nm NAND in SSDs:
- Micron announced on October 16 that start-up Skyera is using Micron’s 128Gb 20nm NAND in its new Skyhawk flash storage appliance
- Intel released the SSD 335 series of client SSDs on October 28 based on 20nm Intel NAND
- SMART announced on October 29 Guardian Technology support for Toshiba/SanDisk 19nm NAND in enterprise SSDs
This represents a real “coming of age” for the 19/20nm NAND flash node. Not only is it being used in SSDs, but it has already found its way into enterprise SSDs and an enterprise storage system. Normally a new technology is used only in client SSDs first, and once it has proven its reliability it is designed into enterprise SSDs. This usually occurs about a year later.
The SSD Guy finds it oddly coincidental that the recent announcements include products based on both IMFT (Intel/Micron) and Toshiba/SanDisk NAND. These two joint ventures compete for leadership in process technology – IMFT ships 20nm planar NAND using a HiK dielectric process and Toshiba/SanDisk manufactures its 19nm product using a more evolutionary process involving air gaps.
It’s also kind of interesting that Toshiba and Micron were not the first to use their own tightest process technology, and that support first came from external partners. This contradicts an argument that I have often heard that the SSD market will consolidate to NAND manufacturers alone since it becomes increasingly challenging to use this technology as process geometries continue to shrink.
These announcements are testimonials to the sophistication of SSD controller technology, which I explain in a series called How Controllers Maximize SSD Life.
In brief, The SSD Guy is very impressed with these announcements. It shows that advancements in NAND management continue, and that users need not worry that NAND will become impossible to use as process geometries continue to shrink.