In a recent study published by Blocks & Files, Solidigm and VAST Data claim that all-flash SSD systems offer a dramatically lower 10-year total cost of ownership (TCO) compared to traditional HDD-based setups—58.9% lower, to be precise. Their analysis pits a VAST all-SSD configuration against a Ceph/Seagate HDD system for supporting 1 exabyte (EB) of data, concluding that SSDs win due to extended warranties, fewer refresh cycles, and data reduction efficiencies. As VP of Product Management at VDURA, a leader in high performance data infrastructure for HPC and AI, I have to laugh when I see these conflated TCO studies whose goal is to somehow convince people that vendors high priced solutions are great value-):
At VDURA, we’re committed to flexibility, allowing customers to mix SSDs and HDDs in whatever ratio suits their workloads—whether that’s all-flash for highest-performance needs or hybrids for balanced performance/capacity storage. This approach directly addresses the pain points in the Solidigm-VAST paper, eliminating frequent HDD refreshes, incorporating advanced data reduction, and delivering superior performance at lower hardware and software costs. What we see in real-world deployments, our flexible hybrid SSD/HDD solutions have delivered over 50% lower upfront acquisition costs compared to all-flash systems like VAST’s, with comparable or lower ongoing operational expenses—proving that optimized hybrids provide superior TCO, performance, and sustainability without the premiums of all-flash. While the study highlights valid points about SSD advancements and superior performance, it overlooks the real-world advantages of systems like ours, which include both all-flash and hybrid SSD/HDD options tailored for the best blend of price, performance, and capacity.
Let’s break this down.
Matching Warranties and Advanced Technologies Eliminate Refresh Cycle Concerns
The Solidigm-VAST study assumes HDD systems require refreshes every four years—two full cycles over a decade—due to wear and failure rates, inflating the TCO to $85.62 million. It cites empirical data showing HDD annualized failure rates (AFR) increasing significantly after the third to fifth year, entering a “wear-out” phase, selectively ignoring data from Backblaze whom recently extending useful life estimates to six years which is more line with standard fleet management practice. In contrast, their SSD setup benefits from a 10-year warranty with no refreshes needed. This is the single biggest factor in their TCO calculation and is flawed. At VDURA we have customers today that are running Hybrid systems beyond 10 years.
VDURA provides an optional 10-year warranty across our all-flash and hybrid SSD/HDD systems, matching VAST’s offering and extending the operational life of components through intelligent tiering and workload management. We acknowledge that HDDs can experience higher failure rates in later years (post 5-6 years), but we’ve developed innovative technologies to mitigate this directly. Our erasure coding, now with Multi-Level, distributes data intelligently to enhance resiliency, while V-ScaleFlow optimizes data flow for balanced wear leveling. VDURA also enables rapid recovery from device-level failures with minimal downtime. Together, these maximize device performance, longevity, and recovery, ensuring that our hybrid systems can operate for the full decade without the need for mandatory full-system refresh cycles—individual device failures are managed through simple swaps, just as they are in SSD-based systems like VAST’s. By dynamically balancing hot data on SSDs and cold data on high-capacity HDDs, we further minimize wear on spinning disks. This removes the “multiple refresh cycles” factor entirely from the equation. As a result, our TCO for 1 EB over 10 years is significantly lower than the study’s HDD baseline and significantly better than all-flash at that scale, thanks to our ability to fine-tune the SSD/HDD mix for the lowest overall costs without massive upfront capital outlay.
Data Reduction Isn’t Exclusive to All-Flash
A core advantage touted in the study is VAST’s data reduction technologies, achieving a 2.5:1 ratio, plus lower erasure coding overheads. This reduces required SSD capacity to just 0.456 EB for 1 EB of usable data, cutting hardware needs and downstream costs like power and rack space.
VDURA’s software suite includes equivalent data reduction technologies as an umbrella capability, optimized for both all-flash and hybrid environments. We’ve seen real-world ratios exceeding 2:1 in enterprise workloads, allowing us to achieve similar efficiencies. Without these, the study admits SSD TCO would balloon to $66.13 million. But with VDURA’s tools normalizing the data reduction factor and a 10-year lifecycle without refreshes, our flexible hybrid systems not only match that efficiency but leverage HDDs’ inherent cost-per-TB edge to deliver substantially lower upfront acquisition costs and overall TCO compared to all-flash systems.
Hardware and Software Costs: Where Flexibility Wins
Once warranties and data reduction are equalized, the debate boils down to hardware and software economics—and here, VDURA’s adaptable approach has a clear lead. Our use of commodity off-the-shelf 1U servers and expansion JBODs (non-high-availability configurations) keeps hardware costs comparable to or lower than proprietary all-flash enclosures like VAST’s Ceres, with fewer custom components, easier scalability, and reduced acquisition expenses.
With these commodity servers minimizing overhead, the primary differentiator becomes the cost of the storage media itself. Even today, HDDs maintain a >6x advantage in price per TB over SSDs, enabling our hybrid systems to deliver vastly lower TCO by blending the two for optimal economics. We avoid over-relying on premium QLC SSDs, instead leveraging reliable HDDs where capacity cost trumps speed. For instance, in a typical VDURA hybrid configuration supporting 1 EB of usable data (assuming similar data reduction efficiencies), where 80% of the raw capacity comes from 30TB HDDs and 20% from flash, the media cost alone is reduced by approximately 67% compared to an equivalent all-flash setup—driving down upfront acquisition prices significantly. Even factoring in operational expenses like power and space (which scale with system footprint but remain competitive in our optimized designs), the overall 10-year TCO is markedly lower than the $35.19 million cited for VAST’s all-SSD system.
On the software side, VDURA’s flexible subscription model amplifies this edge: as we offer lower cost per licensing for HDD based capacity vs flash-based capacity. Unlike VAST’s one size fits all higher per-TB fees for all-flash, our approach keeps ongoing costs minimal, especially for capacity data in hybrids.
Addressing Power, Carbon, and the Pure Storage Response
Just as we challenged Pure Storage’s similar claims a year ago in our engineering blog “Purely Misleading, Carbon Smart Storage,” their latest rebuttal recycles biased tactics to promote Direct Flash Modules (DFMs) as superior in power (up to 4.8x lower) and carbon emissions, using a 10 MB/sec/TB device level benchmark and 5-year HDD lifespans. They decry HDD “performance-per-TB collapse” while ignoring system-level realities.
It’s clear that Pure’s all-flash lens limits their view, but let’s unpack the flaws:
First, they repeat the trick of shortchanging HDDs (and even SSD’s) with 5-year lifespans based on the HDD/SSD device manufactures standard warranties (driving replacements and higher emissions) while granting DFMs 10 years (system vendor warranty). This skews everything in DFM’s favor, but VDURA’s media-agnostic 10-year warranty levels the field for both SSDs and HDDs, incorporating advanced resiliency like multi-level erasure coding to minimize failures without refreshes.
Second, enclosure comparisons are rigged: as we highlighted last year Pure’s spreadsheet model pits ‘modest’ 2U 24-drive HDD setups against denser 5U DFM configs. Real-world standards, as we use at VDURA, include 4U enclosures packing 100+ drives—yielding 68% density gains with 30TB models, slashing rack space, power, and CO2e by up to 73% versus all-flash,
Third, their performance-per-TB critique is actually a device level metric that they are conflating to use to compare systems selectively and it ignores hybrids: VDURA writes/reads hot data from flash, bridging gaps, while colder HDD data benefits from parallel access where multiple drives deliver >10 MB/s per TB collectively with far less than the 50% device level degradation they cite (data written to HDD is always sequential in our software)—proving structured systems outperform isolated device metrics.
These vendors contortions are all designed to dodge the core truth: HDDs dominate capacity economics. For customers/use cases that require the highest performance with significant budget flexibility, then all-flash works great; however, for more holistic performance: capacity: cost, hybrids make a lot of sense. VDURA’s agnostic approach—free of biases—lets us configure anything from 100% all-flash to hybrid that offers flexible ratios of flash/HDDs, enables us to best meet your needs.
Seagate, a key partner in HDD technology, echoes these advantages. Dave Mosley, CEO of Seagate, has long championed the enduring value of HDDs in flexible setups. As he stated in a recent earnings call, “HDD solutions offer approximately six times lower cost per terabyte” compared to SSDs, a gap that widens at hyperscale. These insights align perfectly with VDURA’s philosophy: Storage shouldn’t be one-size-fits-all; flexibility in blending SSDs and HDDs delivers unbeatable TCO.
This perspective is further supported by a recent article in The Register covering Hyperscale storage strategies at Google, where researchers revealed the company’s ongoing reliance on hybrid HDD and SSD setups for optimal TCO at scale. As noted, “Google has revealed that it still relies on hard disk drives for most of its storage needs,” and “SSD-only storage still poses a substantial cost premium over a blended storage fleet of SSD and HDD.” The challenge, they explain, is “putting the right data — the data that gets the most I/Os or needs the lowest latency — on SSD while keeping the bulk of the data on HDD,” emphasizing that hybrid approaches, powered by intelligent data placement as with VDURA, dramatically improve performance and efficiency while maintaining lower costs.
Finally, performance matters: VDURA solutions outperform VAST and Pure on both a per node basis and also on an aggregate cluster basis delivering superior write and read throughput, IOPS and metadata scalability thanks to being a true parallel file system that is yet easy to deploy, use and manage even at exabyte scale.
In summary, the Solidigm-VAST study—and Pure Storage’s sustainability spin—paint an incomplete picture by comparing all-flash to outdated pure-HDD models. VDURA’s flexible solutions—with all-flash and hybrid options, 10-year warranties, robust data reduction technologies, cost-effective hardware, affordable software, and superior performance—offer a more balanced, economical, and sustainable path forward. Enterprises don’t need to choose between cost, capability, and environmental impact; our tailored solutions provide all three. I’d encourage readers to evaluate VDURA varied offerings firsthand to see the real numbers and see how we redefine storage economics.
About the Author:
Chris Girard, Vice President of Product Management
Chris’s experience spans two decades in high-performance storage and multiple patents in erasure coding, system durability, and storage hardware, Chris Girard has shaped VDURA’s rise as the go-to AI and HPC data platform. His technical fluency—honed at Dell, Seagate, HPE Cray, Cohesity and now VDURA—ensures every platform innovation aligns to empower the real-world performance, reliability and scale necessary in the fastest-moving AI era.