Near-line HDD and high-capacity mechanical storage

Why the concentration exists

Cost advantages maintain HDD relevance despite flash storage advances. HDDs remain 6 to 8 times cheaper per terabyte than SSDs, with 90% of data center storage still on spinning disks. QLC NAND has reached near parity at $0.03 per gigabyte compared to HDDs, yet endurance limits prevent complete replacement of mechanical drives by the end of the decade. HDDs continue to hold roughly 80% of enterprise archival workloads due to cost-per-terabyte advantages.[14][2]

What the evidence shows

Who supplies it

Western Digital and Seagate are the two dominant players, each holding more than 40% of the global HDD market. Western Digital held 42.3% of unit shipments as of early 2026, slightly ahead of Seagate. Toshiba accounts for around 17% of the global HDD market and pursues a more conservative technology strategy, stretching existing mechanical and recording innovations rather than racing into HAMR.[9][15][7]

Critical components come from specialized suppliers. TDK Corporation is an HDD head manufacturer that collaborates with Toshiba on technology development. Resonac Corporation is an HDD media manufacturer that works with Toshiba on capacity advances. Nidec is the world's largest supplier of HDD motors.[12][1]

Western Digital completed the spin-off of its NAND Flash business to wholly-owned subsidiary SanDisk on February 24, 2025, marking Western Digital's complete exit from the SSD market to focus on mechanical hard drives. Western Digital's near-line HDD business, post-separation, focuses on high-capacity 24TB to 32TB+ drives for cloud storage, representing over 80% of total revenue. In Q2 FY2026 (ended January 2, 2026), Western Digital's revenue was $3.02 billion, with gross margins of 46.1% and 100% of its 2026 HDD production capacity under Long-Term Agreements.[17][16]

What it depends on, and what depends on it

Nearline HDDs sit between high-performance flash storage and cold archival tape in the data storage hierarchy. They serve warm-tier datasets that require relatively quick access but do not justify the cost premium of solid-state drives. AI training and inference generate massive data volumes that strain data center storage systems, driving demand for this intermediate tier.[4]

Total HDD capacity shipped is projected to rise from roughly 1.2 zettabytes in 2024 to more than 7 zettabytes by 2029, with the vast majority in high-capacity nearline drives. High-capacity nearline hard drive shipments grew 42% year-over-year in 2024, while overall HDD capacity shipments increased 39% year-over-year. Industry analyst Tom Coughlin projects this dramatic expansion driven by AI infrastructure demands.[5][6]

Manufacturing is concentrated in Asia, with Asia-Pacific accounting for 45% of total HDD shipments. Western Digital's factory in Thailand produces more than 100,000 enterprise-grade hard drives daily. Western Digital has approximately 3,000 active HDD patents, and over 180 million HelioSeal drives have been deployed since their introduction in 2013.[3][18][11]

Where it sits in the stack

What would break it

Component shortages compound the constraint. Many component supplies are on a 52-week allocation, according to Seagate's chief technologist. No significant new HDD or NAND fabrication capacity is expected in the near term as facilities take years to set up. Availability issues may linger for years as a result.[10][4]

What to watch

Capacity expansion is underway at the component level. In May 2026, Resonac announced it would increase its HDD recording media output from approximately 160 million disks per year to approximately 210 million, a 31% increase. For the fiscal year ending March 2027, TDK forecasts that nearline HDDs for data centers will grow by 7%.[20]

Technology roadmaps point to significant capacity increases. Western Digital plans to begin mass production of 40TB-class HDDs in the second half of 2026 and targets 100TB HAMR-based drives by 2029. Western Digital's vertical laser technology is expected to increase HAMR platter areal density from 4TB to 10TB per platter by 2028, with a 12-platter platform first used with 60TB ePMR drives in 2028.[9][8]

Product launches are scheduled through 2028. Western Digital began shipping samples of its 40TB HAMR-enabled drives in early 2026. Seagate began shipping 44TB hard drives with HAMR technology to data centers as of March 3, 2026. Western Digital plans to launch 36TB CMR versions and 44TB UltraSMR versions of HDD products in 2026. Western Digital's dual-pivot actuator technology will become available in 2028, and the company plans to launch an intelligent software layer with an open API in 2027.[15][13][17][19]

Related nodes

Sources

1. tomshardware.com · 2026-05-07T11:00:00
2. techtimes.com · 2025-12-16T17:35:10
3. industryresearch.biz · 2026-04-01T00:00:00
4. sealingtech.com · 2026-03-31T10:00:37
5. gillware.com · 2026-07-06T11:48:02
6. horizontechnology.com · 2025-12-04T22:46:29
7. horizontechnology.com · 2026-07-06T12:32:07
8. tomshardware.com · 2028
9. trendforce.com · 2026-07-22
10. datacenterdynamics.com · 2026-03-17
11. westerndigital.com · 2013
12. toshiba-storage.com · 14.05.2024
13. en.wikipedia.org · 2026-03-03
14. markets.financialcontent.com · late 2025
15. markets.financialcontent.com · early 2026
16. markets.financialcontent.com · March 31, 2026
17. semicone.com · 2025-03-10
18. connectedmanufacturing.wbresearch.com
19. blocksandfiles.com · 2028
20. xenospectrum.com · May 2026