Despite the push in 2024 for faster storage, most business-critical data that isn't in high demand is being stored on HDDs. With SSDs now being sold at over 100 TB each, experts weighed in on how much longer HDDs will be able to stay on top.
AI has ushered in an era where high performance is critical, at least in certain instances. HDDs are known for their low cost per gigabyte of storage -- not for their high speeds. HDDs have long been the primary data storage footprint in enterprises, but the rising demands on performance might see flash storage -- a much faster but more expensive type of storage -- begin to make larger inroads into the HDD's footprint.
SSDs have been overtaking HDDs in the last few years, but HDDs still dominate in the enterprise, with just over 85% of the primary data footprint, according to Ed Burns, an analyst at IDC who specializes in hard drives.
"That's going to go down over time -- but gradually," Burns said.
AI and performance
This year, increasingly dense SSDs have been on the rise, with the highest available for purchase scaling from 61 TB to over 120 TB in 2024. Along with higher performance, there is a demand for higher compute, which requires more power and can be potentially gained through a consolidation of storage arrays with denser SSDs.
While some vendors are pressing for innovation such as increased density, others are figuring out how HDDs and flash can work together to meet these demands. In June, Western Digital unveiled a storage framework for AI, the AI Data Cycle, that includes HDDs for cost-effective bulk storage. Software-defined parallel processing vendor Vdura also uses HDDs in the same way in the latest release of its data platform in November.
By combining HDDs and SSDs to meet performance and compute demands, vendors can present a more cost-effective product to customers than a pure SSD offering alone. The gap in price between SSDs and HDDs shrunk in 2023, but didn't narrow further in 2024, according to Ken Claffey, CEO of Vdura. And the reality is that when it comes to storage requirements, customers don't make decisions based on performance needs alone -- they also consider their budget.
"If flash is expensive, I need to be able to get the performance my customer needs and the capacity with a minimum amount of flash and more HDDs," Claffey said in reference to Vdura's composable nature that enables more HDDs to be added.
Marc Staimer, president of Dragon Slayer Consulting, noted that customers must consider use cases before making an investment.
"Unless you're running a primary, mission-critical workload, you don't need the performance of SSDs," he said.
Data management infrastructure such as data lakes as well as data types including object storage are core to AI workloads and are adequately supported by HDDs, according to Staimer.
Big drives, big risks
In November, Solidigm and Phison both released quad-level cell SSDs with over 120 TB of capacity, while Micron released a triple-level cell SSD at 60 TB. In December, SK Hynix added a 60 TB SSD to its lineup. On the HDD side, both Western Digital in October and Seagate in January started shipping 32 TB drives, with the latter shipping a heat-assisted magnetic recording version. All-flash array vendor Pure Storage started shipping a 150 TB version of its proprietary SSD-like DirectFlash Module in its arrays.
High-density SSDs can narrow the price gap between SSDs and HDDs, but use cases for such density are still limited, according to Jeff Janukowicz, an analyst at IDC.
"Are 128 TB SSDs going to find homes everywhere? Probably not, but there certainly are some workloads and infrastructure implementations where really high-capacity drives can be advantageous," Janukowicz said.
High-density SSDs are fairly new, but whether they take off in sales is yet to be seen, Staimer said. One drawback is the high costs associated with the size of the drives. SSD and HDD high-density drives are currently aimed at hyperscalers, and whether they are adopted by enterprises will come down to costs, he said.
A larger concern is around drive failures, according to Staimer.
"The real issue is, if the controller fails, how long will it take you to rebuild 120 TB?" he said.
Parity vs. TCO
HDD vendors often argue that the market is still a long way from cost parity, with SSDs currently priced four to five times higher than HDDs, according to Joseph Unsworth, an analyst at Gartner. SSD vendors, on the other hand, tend to emphasize total cost of ownership, which includes energy savings and longer refresh cycles, although this can depend on array refreshes.
While it might not be needed to surpass HDDs, reaching cost parity would be useful to SSD sales, Unsworth said.
There's not enough flash capacity to soak up all those hard drives.
Joseph UnsworthAnalyst, Gartner
"If flash is going to challenge nearline drives, which are going for a little over one penny per gigabyte, it will be very difficult to get to parity," he said.
Beyond these challenges, SSD vendors still face the issue of scale, Unsworth added.
"There's not enough flash capacity to soak up all those hard drives," he said.
Fabs are expensive and take time to build, Unsworth said. He believes flash will continue to make inroads into the HDD's footprint, but it won't happen overnight or in the next few years.
No more HDDs by 2028?
Not everyone agrees with that time frame. In 2023, all-flash array vendor Pure Storage stated that, in five years, no net-new hard drive systems would be sold. Shawn Rosemarin, vice president of R&D for customer engineering at Pure Storage, echoed that prediction more recently, saying that nearline systems will move to flash as they are refreshed.
"I do strongly believe that there will be no net-new nearline systems sold by the end of 2028," he said.
Rosemarin argued that even hyperscalers, the primary customers of HDDs, will see the density, performance and TCO advantages of switching over to flash in the coming years.
This isn't the first time the death of HDDs has been theorized -- but these predictions are often overstated, IDC's Burns said.
"[The HDD vendors have] a roadmap to develop new products well into the future, well beyond 2028," he said.
The best storage is relative to what customers are trying to achieve, Burns said. If the budget has a limit, and performance isn't the main goal, HDD-based systems will still be purchased, net-new or otherwise.
Adam Armstrong is a TechTarget Editorial news writer covering file and block storage hardware and private clouds. He previously worked at StorageReview.
