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Follow the HDDs: What This Week’s WDC and Seagate Earnings Tell Us About AI Storage

Follow the HDDs: What This Week’s WDC and Seagate Earnings Tell Us About AI Storage

The receipts are in on every claim made in “The Flash Emperor Has No Clothes,” and a closer look at which drives the hyperscalers are actually buying.  – By Erik Salo, SVP Marketing & Business Operations, VDURA 

A week ago, our CEO Ken Claffey published “The Flash Emperor Has No Clothes,” arguing that the all-flash array industry built a decade-long pitch on a premise that was never true and has now publicly collapsed. The piece was deliberately provocative. 

This week, two earnings reports made the case for us. No rhetoric required. 

The receipts 

On April 28, Seagate (STX) reported Q3 FY26 revenue of $3.1 billion, up 44% year over year. Non-GAAP gross margin hit 47%, an all-time high. Data center demand accounted for 80% of revenue, and nearline drives, the high-capacity HDDs sold predominantly into hyperscale and cloud customers, represented close to 90% of total exabyte shipments. Seagate raised annual growth guidance to at least 20%. The vast majority of nearline capacity is already allocated through fiscal 2027. 

The same week, Western Digital (WDC) reported Q3 FY26 revenue of $3.3 billion, up 45% year over year. Cloud revenue grew 48% YoY and represented 89% of WDC’s total revenue. Gross margin exceeded 50%. Multi-year customer agreements now extend into 2028 and 2029. 

Combined, these two HDD vendors did $6.4 billion in revenue last quarter. Roughly 85% of that over $5.4 billion came from hyperscalers, cloud service providers, and large data center customers. The contracts behind those numbers run for years. 

This is what the hyperscaler vote looks like in market-data form. The largest data infrastructure operators on earth are not just buying HDDs, they are buying them at record rates, on multi-year commitments, while continuing to invest aggressively in NVMe flash for performance tiers. 

If “flash is the new HDD” had ever been true, you would not see this. You would see HDD revenue declining, not growing 44–45% year over year. You would not see $6.4B quarters and contracts running through the end of the decade. 

The hyperscalers run mixed fleet. Period. 

This is the architectural pattern Ken’s piece described, now visible in two public earnings calls in a single week. The leaders run mixed-fleet, software-defined storage: high-performance NVMe flash for hot data and metadata, high-density HDD for capacity, all unified by software they either built or licensed. Just enough flash to saturate workload performance, then HDD for everything else. 

This is not a hedge. It is not a transition state. It is the steady-state architecture for the largest AI and cloud workloads on the planet, and the multi-year contract durations on those earnings calls confirm it. The hyperscalers are committing through 2028 and 2029, past at least three more potential AI-driven NAND cycles, to a mixed-fleet design. 

The detail nobody is talking about: which HDDs they’re buying 

Here is where the story gets more interesting, and where the architectural argument sharpens. 

The HDDs Western Digital and Seagate are shipping in record volumes are not the kind of drives that go into legacy hybrid architectures. They are not dual-ported SAS drives. They are: 

  • Single-port SATA — the commodity interface used in software-defined, shared-nothing architectures. No HA controller dependency, no proprietary backplane, no firmware lock-in. 
  • HAMR (Heat-Assisted Magnetic Recording) — Seagate’s Mozaic 4 platform. Highest capacity drives in the market. Seagate’s earnings call explicitly stated HAMR exabyte output is expected to become dominant by late 2026. 
  • SMR (Shingled Magnetic Recording) — including Western Digital’s UltraSMR family. WDC’s earnings call called out SMR adoption specifically as a margin and TCO driver. 

These three categories: single-port SATA, HAMR, SMR share one important architectural property. They are designed for software-defined, shared-nothing storage systems. They are not the drives legacy hybrid architectures DDN Lustre, NetApp ONTAP, and the rest were built around. Those systems require dual-ported SAS for controller failover. They cannot natively consume, at scale, the drives the hyperscalers are buying by the exabyte. 

In other words: the hyperscalers are buying record volumes of exactly the drive classes that legacy hybrid architectures cannot natively consume. 

This is the second-order proof point of the mixed-fleet thesis. It is not just that the hyperscalers are buying HDD. It is that they are buying the kind of HDD that confirms a specific architectural model: software-defined, shared-nothing, designed around commodity media and by buying it at hundreds-of-exabytes scale, they are pulling the entire industry’s HDD roadmap in that direction. The next decade of HDD innovation will be built for the architecture VDURA HYDRA shares with the hyperscalers, not the legacy hybrid architectures DDN, NetApp, and others built around in the 2010s. 

What VDURA is built for 

VDURA’s HYDRA architecture was designed from inception around exactly this pattern. We are software-defined, shared-nothing, and we run on commodity, hyperscaler-grade media: 

  • Single-port NVMe SSDs (TLC and QLC) for performance tiers 
  • Single-port SATA HDDs (CMR, SMR, HAMR, and emerging HBHDD) for capacity tiers 
  • One software stack, one control plane, one data plane, one global namespace across both media 

This is not a roadmap aspiration. It is shipping today. Our V12 SMR optimization engine delivers 25–30% more usable capacity per rack on SMR drives, and we are actively qualifying the next generation of 40 TB+ HDDs across the major suppliers. The same software handles single-port SSD and single-port HDD natively, with full parallel performance and object-grade resilience across both. 

Translation: the same drive classes WDC and Seagate just reported record demand for from hyperscalers are the same drive classes VDURA HYDRA is built to consume — and to pair with high-performance NVMe flash in a unified mixed-fleet system. We are bringing the hyperscaler architecture, with the hyperscaler media, to every AI factory, Neocloud, and research institution that needs it. 

Two weeks, two confirmations 

Ten days ago, an open letter from one all-flash CEO admitted the central economic premise of all-flash had run out of road for the foreseeable future. This week, $6.4 billion of public earnings revenue concentrated almost entirely in hyperscaler and cloud customers, with contract durations extending into 2028 and 2029 showed who is already operating on the next chapter, and what they are buying to build it. 

The signal is loud, and it is consistent. Mixed fleet is the present. The contracts running through 2029 say it is the future as well. The architectural question for any organization buying AI or HPC storage in 2026 is no longer whether to embrace mixed fleet, but how quickly to deploy a platform that does it natively, on the same drive classes the leaders are buying. 

VDURA HYDRA is built for exactly this. The receipts are public. The contracts are signed. The drives are shipping. 

The architecture argument is over. Mixed fleet won the market — $6.4 billion of revenue this week, hyperscaler contracts running through 2029, and a roadmap of single-port SATA, HAMR, and SMR drives that legacy hybrid architectures cannot even consume. The only question left is how quickly the rest of the industry catches up. 

Sources & further reading: 

Erik Salo is SVP of Marketing & Business Operations at VDURA. A former VP at Seagate and Chief Strategist at AMD, he leads VDURA’s flash economics research and the Flash Volatility Index.