Are SSDs Going to Replace HDDs Down the Road?

Does it make sense to claim that Solid State Drives (SSDs) will take over enterprise storage in the foreseeable future? Many of us are oblivious to the answer and tend to go with the popular notion that is spreading like a bug. The battle between HDDs and SSDs to emerge as a dominant storage media entails several insights. Let us take a peek into the economics and search for the truth in technology.

Performance

There is no arguing to the fact that SSDs are faster than HDDs. The performance of SSDs is significantly high when carrying out random I/O data reading. But when it comes to large block sequential data (as with rich media like videos), you might not observe a notable difference.


Storage in Numbers

The claim that SSDs will replace HDDs is not yet backed by the economics. The amount of data generated in the last year was approximately 2500 exabytes. In the next two years, this amount will double. Let us take a look at the amount of storage produced to accommodate this much data. The NAND flash industry contributed to addressing only 1.4% of the total storage need. This manifests in itself that only SSDs cannot keep up with the increasing storage needs.

Are SSDs Getting Cheaper?

Yes. The NAND flash industry aims at shrinking line widths further (to 19nm or 16 nm). In addition, the storage density has increased due to the use of MLC-based NAND (instead of SLC-based NAND). This paves the way for reducing the cost of solid state storage.

The same scenario was observed with HDDs due to their areal density increases. However, the density growth has slowed down as of now. Further, the next-generation technology (HAMR) will not come to HDDs shortly as it requires a huge investment. This implies that the HDD costs won’t see a major change until we move to this technology.

The same facts are true for the NAND flash industry too. The shrinking line widths make flash more susceptible to write exhaustion. To do away with this problem, various error-correction algorithms are built into SSDs that result in overprovisioning of these drives. This adds to the storage cost. The cost gap is not likely to close in the foreseeable future.

From the above arguments, it is apparent that SSDs won’t take over the mechanical storage. HDDs have done a good job of serving the storage requirements of enterprises to date. They have been successful in addressing both the capacity and performance needs. However, the storage infrastructure solutions employing HDDs have created higher power requirements and led to system overprovisioning. This is where the use of SSDs comes into play. SSDs when used together with HDDs can minimize overprovisioning and increase performance. A thin provisioning of performance and capacity can cut costs significantly.