Seagate plans hard drives over 50 TB

A tiny laser works directly at the write head: It heats the surface of a hard drive for a brief moment before a bit is stored. With this HAMR technology, Seagate plans to ship its first drives in the 50-TB class for customer qualification at the end of 2027—initially not for the broader market.

Seagate is already shipping its Mozaic-4+ platform with up to 44 TB in large volumes to two unnamed hyperscale cloud companies. The drives use more than 4 TB per platter and ten platters in a 3.5-inch enclosure. The localized heating makes it possible to switch particularly small, magnetically stable bits with a manageable magnetic field strength.

For Mozaic 5+, Seagate cites more than 5 TB per platter. With ten platters still in use, that adds up to the announced 50-TB class. Following validation by OEMs and cloud operators, broader availability is expected, which according to the roadmap is more likely in 2028 than 2027.

And then? For operators of large data stores, the practical limit moves higher still: More data can be stored on mechanical drives, whose cost per terabyte remains lower than that of SSDs, according to heise online. This is particularly relevant for cloud storage, while SSDs remain superior in data transfer rates and latency.

Demand is already high. As a result of the AI boom, Western Digital’s and Seagate’s production allocations for 2026 were largely sold out early; the situation is likely similar at Toshiba. Seagate is looking at drives with up to 100 TB in the long term, but the 50-TB models still first need customer qualification and a transition to broader availability.