Seagate ST24000NM002H 24TB 7200RPM SATA 6Gb/s 3.5in Exos X24 Hard Drive

The Seagate ST24000NM002H is the 24TB SATA drive that launched as the Exos X24. Seagate has since folded its X-class drives into a single Exos family, so its current data sheet lists this same model number simply as the Exos 24TB. It is a helium-sealed, 7200 RPM, 3.5-inch CMR drive with a 512MB cache, a sustained transfer rate of up to 285 MB/s and an MTBF of 2.5 million hours.

This is the highest-capacity drive in this group, built for dense nearline storage: backup and replication targets, object stores, data lakes, AI and analytics data sets that are written once and read many times, and large surveillance archives. Seagate's product manual rates it for up to 550TB of workload per year. It is not a substitute for 10K SAS or SSD tiers where random I/O sets the pace.

The ST24000NM002H is the standard model with Seagate Instant Secure Erase (ISE), a feature for erasing the drive quickly when it is retired, and it is not a managed self-encrypting drive. The SED version is ST24000NM001H. The interface is single-port SATA 6Gb/s. For dual-port SAS, Seagate's 24TB part is ST24000NM007H. The drive ships as 512e and supports conversion to 4Kn through FastFormat, which deletes all data on the drive.

Points to check before you order:

• Controller and NAS support for 24TB drives. Older HBAs, RAID firmware and NAS models may need an update or may not list this capacity.
• Rebuild planning. Rebuilding a 24TB member takes a long time, so dual-parity RAID or erasure coding is the usual choice at this size.
• Carriers. It is a bare drive, and HPE or Dell servers need their own carriers and may flag non-OEM firmware.
• Power per bay. Seagate lists 6.3W at idle and up to 8.9W under random load.