Who’s Winning the SSD Race? Ask the Patents
Traditional spinning hard disk drives (HDDs) have dominated datacenters since their inception, primarily due to lower upfront cost per gigabytes ($/GB) and the lack of other feasible storage options. This has begun to change in the last decade, since the cost of solid state drives (SSDs) started dropping.
Considering the demands of modern datacenters, which typically are dominated by virtual machines (VMs) and big data analytics, SSDs offer superior performance. This is important since cloud providers like Microsoft have begun to deliver premium storage with lower latency for big data applications on cloud databases.
From a pure cost standpoint, two factors are driving datacenter storage solutions towards solid-state drives. Firstly, SSDs offer a much lower operational, and in select cases, lower overall capital cost than HDDs. It is true that hard disk drives still offer significantly lower cost per gigabyte. However, if we take into account other factors such as cost per transaction, the cost of Input/Output operations per second ($/IOPS), and IOPS per watt, then SSDs begin to offset their higher purchase price per gigabyte.
The second factor driving adoption of SSDs is that the cost per gigabyte is falling. This decline is due to Moore’s Law and 3D stacking of memory cells used in SSDs. Moore’s Law allows for denser memory cell circuits that result in lower overall cell cost due to transistor scaling.
There are other considerations we should take into account as well. For example:
- HDDs require over provisioning due to I/O blender effect from virtualization of storage, which is minimized in SSDs.
- SSDs consume less power and generate less heat, resulting in lower utility bills and cheaper cooling systems.
- Solid-state drives occupy <2x smaller space than comparable capacity hard disk drives and as 3D stacking technology advances, their size is expected to reduce further.
- SSDs have lower latency, thus improving the responsiveness of applications, and shorter boot times.
- Solid-state drives also have longer life and higher reliability because they do not have moving parts like hard disk drives.
According to the research conducted by our team at LexInnova, the majority of R&D in SSD technology has been in 3D NAND, which is the most important technology for increasing the capacity and lowering the cost per gigabyte of storage drives. Today, 3D NAND based SSDs are available in the market, and are expected to be widely available by early next year.
As 3D NAND is proving to be a game changing technology for storage, it is safe to assume companies that have the strongest IP portfolios in this technology will be the most well positioned to emerge as market leaders. Gleaning from an IP report on 3D memory which LexInnova recently published, SanDisk, Micron, and Samsung are the top three patent assignees of this technology with 829, 219, and 194 patents/patent applications respectively. The number of patents/patent applications owned by the top three assignees comprise around 54 percent of the total patents/patent applications (around 2,300) filed in this domain.
Top assignee SanDisk shares a fabrication plant with Toshiba which also appears among the top seven assignees in 3D NAND technology. Samsung is also working on its own 3D stacked memory and has released several iterations of it. Also, several companies are entering into partnerships to leverage their IP portfolios and share cost of manufacturing resources. Recently, Micron Technology announced that it was working with Intel to release 10TB flash memory in a 2mm chip by the end of this year.
Geographically, the United States has seen the most patent filings in the domain of 3D NAND technology, followed by China, Japan, Korea, and Taiwan. SanDisk is the top assignee in the United States with 425 patents.
Apart from having the most patents in its portfolio, SanDisk’s portfolio is also exemplary in terms of quality based on LexInnova’s research. Briefly, “good quality” patents meet numerous criteria: They have good technological implications and many other assignees cite them; have been published in major markets; they were successfully granted after being filed; are broad enough to have a good chance of finding potential licensees and real-world applicability; and cover multiple aspects of a technology. HP, Rambus, and Hitachi also have good quality patents, but lack in filing activity, meaning there are fewer actual patents filed, according to our research. Taking a more granular look, Hitachi has the most high quality patents owing to a large number of patent citations, while HP’s patents have the one of the best technological coverage. IBM, Intel, and AMD lack on both patent quality and quantity of filings. Also, they have filed most of their patents recently (between 2012 and 2014), which hampers their quality. The quality of their portfolios could improve further in the future after successful grant of patents that are still in the application stage, and the addition of more citations.
Looking at the various technology sub-domains in the field of SSD technology, licensing activity is expected to be the highest in model parameters related to contact formation (FEOL); operating speed in contact formation (FEOL) along with structural features related to assembly/packaging. This is mainly because the patents related to these sub-domains are highly fragmented and distributed among a number of players.
Based on the strengths of their IP portfolios and significant investments in R&D, one can expect SanDisk, Samsung, and Micron to dominate the SSD market for datacenters in the years to come.
Editor's Note: This article was revised from its original format to reflect SanDisk's acquisition of Matrix Semiconductor in 2005.
About the Author
Rana Pratap is Principal Consultant - Technology at LexInnova, a patent and litigation consulting firm. He has over 15 years of experience working for leading technology companies in Silicon Valley, and regularly consults on issues related to semiconductors and other associated technologies. Learn more about Rana by visiting his profile on LexInnova's website.