At the start of 2026, the global storage industry delivered a set of results that exceeded most expectations. Seagate (NASDAQ: STX) reported fiscal Q2 2026 revenue of $2.83 billion, up 21.5% year-over-year, with adjusted earnings per share reaching $3.11, a 53.3% increase—both metrics beating market forecasts. During the same period, Western Digital’s revenue rose 25% year-over-year to $3.02 billion, with net profit surging 296%. These two HDD giants posted their best results in a decade almost simultaneously.
Yet, in most AI-related discussions, the focus remains on GPU computing power, HBM memory, and Ethernet switches. Hard disk drives (HDDs)—a technology nearly seventy years old—seem far removed from the core narrative of this AI wave. However, the data tells a different story: In FY2026 Q2, Seagate’s data center business accounted for 79% of total revenue, reaching $2.2 billion, up 28% year-over-year. AI hasn’t bypassed HDDs; instead, it’s fundamentally reshaping data center storage architecture. HDDs are experiencing a structural demand surge driven by AI.
A Defining Turning Point in Supply and Demand Dynamics
To understand the core of Seagate’s current growth, we need to address a fundamental question: Is the demand growth for HDDs sustainable?
On the supply side, Seagate CEO Dave Mosley stated clearly during the earnings call that the company’s nearline high-capacity HDD production is fully booked through the end of calendar year 2026. Customers are more concerned about "stable supply" than price, and orders are now scheduled into 2027. This signals a shift in the HDD market from cyclical fluctuations to a structurally tight supply environment.
On the demand side, this change is driven by AI workloads restructuring storage architecture. Massive datasets used in training need to be preserved long-term for ongoing iteration, while Agentic AI in the inference phase requires access to vast historical data to perform complex tasks. Mosley noted that as AI-generated video content surges, demand for exabyte-scale storage will continue to grow. Every stage of generative AI—from data collection and model training to inference output—creates data that must be retained long-term. As the primary medium for cold and warm storage, HDD demand is directly tied to the scale of AI infrastructure expansion.
Key metrics: In FY2026 Q2, Seagate achieved a GAAP gross margin of 41.6% and a non-GAAP gross margin of 42.2%, both record highs. Higher margins indicate stronger pricing power, which stems from customers’ willingness to pay a premium for high-capacity HDDs in a supply-constrained market. The report also showed Seagate generated $607 million in free cash flow in Q2, with a healthy balance sheet.
Comparing HDDs with another key storage medium—NAND—further highlights the structural nature of demand. Third-party research from Dolphin Analyst indicates that between 2026 and 2027, demand growth for DRAM, NAND, and HDD will all outpace supply, keeping storage markets tight. The difference is that NAND capacity can be expanded by stacking more layers without building new production lines, while Seagate and Western Digital have been far more restrained in expanding HDD capacity. The industry has tacitly adopted a "controlled supply and price adjustment" strategy to maintain tight supply-demand balance and maximize profitability.
Historically, during the last storage downturn (2022–2023), Seagate faced two years of declining profits—a lesson not forgotten. Now, with a duopoly in place, neither player is interested in repeating the boom-and-bust cycles caused by uncontrolled expansion. Supply discipline, combined with AI-driven structural demand, forms the core logic supporting Seagate’s sustained profitability.
Analysts have reached a consensus on this view. Citi raised its STX price target from $740 to $1,150, maintaining a buy rating; Barclays increased its target to $1,000; and BofA raised its target from $320 to $400. The 12-month average price target among 22 analysts is $847.68, with the highest estimate at $1,150. These upgrades are all based on the same core factors: AI-driven storage demand, industry supply discipline, and the pricing flexibility of high-capacity HDDs.
HAMR Mozaic Technology Roadmap: From Lab to Exabyte-Scale Deployment
Seagate’s Mozaic platform marks the commercial rollout of HAMR (Heat-Assisted Magnetic Recording) technology and is a major differentiator from Western Digital’s technology roadmap.
HAMR’s core innovation is to break through the physical limits of conventional perpendicular magnetic recording (PMR). Traditional HDDs are limited by the superparamagnetic effect—when magnetic grains become too small, thermal fluctuations can destabilize data. PMR is nearing this physical boundary. HAMR uses nanoscale laser spots to create a momentary high-temperature zone (lasting less than 1 nanosecond) on the disk surface, allowing the write head to record data in this window. Once the laser moves away, the medium cools instantly, locking in the data. Essentially, HAMR leverages photonic engineering to achieve a massive leap in areal density, trading energy input for physical space.
The evolution of the Mozaic platform clearly demonstrates Seagate’s mass production capabilities in HAMR technology. In 2024, Seagate launched the first-generation Mozaic 3+ platform, achieving over 3TB per platter, with nearline HAMR shipments exceeding 1.5 million units in a single quarter. By March 2026, the second-generation Mozaic 4+ platform was certified by two hyperscale cloud providers and entered mass production, boosting single-platter capacity to over 4TB and enabling 44TB per drive with a 10-disk assembly. Vertical integration of photonics is a key feature: Seagate designs and manufactures its own lasers, embedding them directly into wafer processes, moving from purchased laser modules to in-house wafer-level integration, and eliminating cumulative assembly errors. This decision shortened customer certification cycles—Mosley noted on the earnings call that Mozaic 3 has been certified by all major US cloud providers, and Mozaic 4+ completed testing with two top cloud customers ahead of schedule.
Looking ahead, Seagate aims to achieve 10TB per platter and push total drive capacity toward 100TB.
Similar to SSD process evolution, HAMR’s areal density improvements decouple capacity growth from physical size and energy consumption. For hyperscale data centers, this means they can expand effective storage capacity without increasing floor space or power usage—a value that becomes even more significant at exabyte-scale deployments.
Within the industry, Western Digital also benefits from AI data center HDD demand but follows a different technical path. In FY2026 Q2, Western Digital posted $3.02 billion in revenue, surpassing Seagate, with high-capacity nearline HDDs driving most of the growth. The two companies now form a duopoly in HDDs, with similar gross margins (Seagate at 42.2%, WD at 46.1%), but Seagate currently leads in HAMR commercialization and single-drive capacity.
Why Do AI Hyperscale Data Centers Still Rely on HDDs?
A common misconception in AI data center storage architecture is viewing SSDs and HDDs as substitutes. In practice, they work together in a tiered system—SSDs handle hot data and caching, while HDDs store large volumes of cold and warm data. This structure balances cost efficiency and performance, and at exabyte scale, the total cost of ownership (TCO) difference becomes even more pronounced.
The unit storage cost gap between SSDs and HDDs is widening. VDURA reports that between Q2 2025 and Q1 2026, the price of a 30TB enterprise TLC SSD will soar 257% from about $3,062 to nearly $11,000, while HDD prices will rise only about 35% over the same period. The unit capacity cost ratio will jump from 6.2x to 16.4x—meaning enterprise SSDs now cost nearly 16 times more per TB than HDDs. VDURA further compares three-year TCO for hybrid storage versus all-SSD solutions: Hybrid costs about $5.99 million, while all-SSD costs $25.2 million—just one-quarter for the hybrid approach.
This gap has significant implications for exabyte-scale deployments. Currently, more than 80% of data center storage capacity is still HDD-based. Global data volume is projected to grow from 72 ZB in 2020 to 527 ZB by 2029, and as of now, 87% of cloud storage still relies on HDDs. For cloud providers planning tens of exabytes of capacity, the cost gap between HDD and SSD is a decisive factor in storage architecture.
The leap in single-platter capacity with Mozaic 4+ further amplifies HDD’s TCO advantage. At a 1 EB deployment scale, the 44TB drive solution reduces infrastructure needs by about 47% compared to 30TB drives: The number of HDDs drops from roughly 33,300 to 22,700, saving about 800,000 kWh of electricity annually and shrinking data center space by about 100 square feet. Mozaic 4+ also boosts per-rack and per-watt capacity, enabling storage expansion without increasing physical footprint or energy consumption.
To summarize the cost structure: Mozaic 4+ technology decouples marginal storage capacity costs from physical resource input, instead driving them through areal density improvements. For cloud providers expanding AI data centers globally, this means they can reallocate saved power and space to computing resources, without incurring proportional storage costs.
Trade Seagate Stock on Gate: Diversify Your Investment Portfolio
For investors who believe in the "AI infrastructure value re-rating" represented by Seagate, the stock trading service on the Gate platform is worth considering.
Gate, a global leader in digital asset and blockchain services, has expanded its offerings from cryptocurrencies to US equities. On Gate, users can easily trade high-quality tech stocks like Seagate (STX) without switching between platforms, managing digital assets and traditional securities within a unified account system.
The core philosophy of Gate’s stock trading is "lower barriers, higher efficiency." For users accustomed to the pace of crypto trading, Gate has designed its stock trading interface and parameters with a unified style, making it easy to get started. On the cost side, Gate supports zero-commission trading for US stocks, further reducing user transaction costs.
Trading Seagate stock on Gate is straightforward: First, log in to your Gate account and complete identity verification (KYC). Second, search for "STX" or "Seagate" on the "Stock Trading" page. Third, select your order type (market/limit), enter the quantity, and confirm to complete the trade. The overall experience is similar to spot crypto trading, so users can adapt quickly.
Conclusion
The value chain of AI infrastructure is undergoing a shift from a "chip-centric" to a "full-stack" perspective. While GPU computing power dominates the conversation, the value of data storage remains systematically underestimated. Seagate’s financial performance and technology roadmap provide concrete evidence for a new assessment: sustained revenue growth, record-high margins, Mozaic 4+ entering mass production, and capacity sold out in advance—all signal that HDDs are experiencing a "double whammy" driven by both their technology lifecycle and AI demand. Replacement and expansion needs are being released simultaneously, pricing power is strengthening in a tight supply-demand environment, and HAMR technology is enabling a leap in capacity while reshaping storage economics.
It’s important to note that all investments carry risks. Potential challenges for Seagate include possible yield bottlenecks in large-scale HAMR ramp-up, which could affect delivery of 44TB and larger drives; intensified competition from Western Digital in high-capacity HDDs, which could erode margin advantages; and the historic cyclical reversals seen in the storage industry, which warrant ongoing monitoring. All data cited in this article comes from public financial reports and third-party industry research and does not constitute investment advice of any kind. Investors should make independent decisions based on their own risk tolerance.
