Hard Disk Drive Unit Shipments Could Grow To Support AI Workloads

Hard Disk Drive

getty

The latest Coughlin Associates history and projections for HDD unit shipments are shown in the figure below.

Since C3Q 2025 both Seagate and Western Digital have made it difficult to determine just how many HDDs the companies have shipped per quarter. Instead, the companies have focused on total HDD storage capacity shipments rather than also including unit shipment information.

As a consequence, our projections for HDD shipments in the second half of 2025 through the first two quarters of 2026 are estimates, but we currently predict that there will be a 1.2% increase in HDD unit shipments from 2025 to 2026 after an estimated 0.4% unit-shipment increase from 2024 to 2025.

Our median projection is that unit shipments would grow about 11% from 2026 to 2030. However, recent reports about increasing HDD head manufacturing capacity at the HDD companies as well as TDK may favor higher growth in HDD unit shipments, perhaps as much as a 30% unit-shipment growth from 2026 to 2030, as predicted in the high model in the chart above. Let’s look at these announcements.

‘A recent article in the Minnesota Star Tribune reported that Seagate is expanding its hard disk drive head facility in Bloomington, MN by almost 3X, from 11,000 square feet of clean room space to 19,000 square feet. Magnetic heads are manufactured on ceramic wafers with processes similar to those used for semiconductor manufacturing and they are one of the gating factors in making more hard disk drives. Presumably these new facilities will be making HAMR heads that will also include integrated lasers for heating the magnetic recording media.

In recent investor meetings Seagate had said that they were currently focusing on increasing HAMR HDD production to meet their commitments for overall HDD storage capacity shipments versus increasing HDD unit production volume. While Western Digital has increased the number of disks and heads in their HDDs up to 11, with plans to go up to 14 disks in a drive, Seagate has focused on making HDDs with 10 disks per drive. WDC has also indicated that they are focusing on increasing storage capacity shipments rather than increasing HDD unit shipment volume.

So, an expansion in their head manufacturing probably indicates that Seagate plans to increase HDD unit production capacity when that additional manufacturing comes online, likely 12-18 months from now. That would probably result in additional HDD unit production capacity available from Seagate in later 2027 or 2028.

In April, TDK, who makes HDD heads for Toshiba and sometimes for Seagate and Western Digital also said that they were increasing HDD head production capacity. Although I haven’t seen reports of WDC head production capacity expansion, it makes sense that they would do so, both to support higher component count HDDs as well as to make more high-capacity HDDs to support projected demand.

Recent HDD head manufacturing announcements indicate that the industry will increase unit shipments in addition to overall storage capacity shipments by decade's end.