Is There Still a Future for Hard Disk Drives?

The capacity for solid state drives (SSDs) keeps going up while the price per terabyte keeps falling, sometimes raising questions about the future for hard disk drives (HDDs). Will the cost of SSDs per TB eventually become so low that they will totally displace HDDs?

I decided to ask a couple of experts in the field, Jim Handy from Objective Analysis and Tom Coughlin of Coughlin Associates. I was looking for a comparison projection for HDDs and SSDs that would go about five years out into the future. Jim had performed such an exercise back in 2017, WDC: No SSD/HDD Crossover, but I needed something more recent. Jim had his SSD forecast data, shown in red in Figure 1 and Tom provided the HDD data shown in blue.

Fig. 1: HDD vs SSD $/TB

The slope is steeper for the SSD data, but it does not look like we’ll see a crossover in the next 5 years. The green $4.75/TB point was placed there by me to show readers where that falls on the plot and to use again later in Figure 2.

While the cost per TB is an important question, it’s not the only factor that warrants consideration. The technologies have more to compare than just their cost per unit of storage. It’s interesting to note that in their 1988 published paper, “A Case for Redundant Arrays of Inexpensive Disks (RAID),” D. Patterson, G. Gibson and R. Katz put the word “inexpensive” right into the title, but it’s now also common to see people refer to RAID as, Redundant Arrays of Independent Disks.

In an article, “SSDs Unlikely to Completely Replace Hard Drives,” T.J. Burlee lists the following reasons, among others, as to why HDDs are unlikely to go away anytime soon:

1. Stable and reliable long-term storage
2. Much less expensive option for storing massive data
3. Excellent choice for infrequently accessed data
4. Performance optimized with SSDs in hybrid systems
5. Play an important role in the data storage hierarchy

There are still many business applications where the inherent characteristics of hard disk drives make them a better choice for storage. Perhaps the foremost is the better stability of data on hard disk drives over longer periods of time.

To answer the question about long-term roadmaps for hard disk drives, Seagate’s CEO and CTO shared their HDD roadmap in June at the Seagate Investor and Analyst Event 2025, and based on Seagate’s Heat-Assisted Magnetic Recording (a.k.a. HAMR, technology), the projection is that 150TB drives with 15TB platters are about a decade out. This provides significant room for HDDs to continue to grow in capacity.

With the explosive growth in AI and Big Data, the market projections for the global shipment of HDDs is also expected to be quite robust. Figure 2 (below) shows the growth in yearly shipments of HDDs, SSDs and tape in exabytes. If we use the $4.75/TB figure that I marked in figure 1 (above), that would project out to an ~$57B market for HDDs by 2030. Lucintel is projecting the HDD market to reach $58.7B by 2030.

Fig. 2: Yearly shipments in exabytes for HDDs, SSDs, and tape.

While there are several applications that are very well suited to SSDs, like storage in laptops and high-performance applications, it’s pretty clear that HDDs still have a healthy, viable roadmap and won’t be going away anytime soon.

For readers interested in more about this topic, the Future of Memory and Storage Conference will be held Aug. 5-7 at the Santa Clara Convention Center in Santa Clara, California.