Seagate Exos X24 - 3.5" Enterprise HDD - 12TB SATA SED

The Seagate Exos X24 is Seagate's high-capacity enterprise drive built on Mozaic 3+ recording technology, achieving an industry-leading 3TB per platter. Available in 12TB, 16TB, 20TB, and 24TB capacities, every model runs at 7,200 RPM with CMR recording, a 512MB multisegmented cache, and a sustained transfer rate of 285 MB/s. The X24 carries a 2.5-million-hour MTBF and a 550TB/year workload rating, making it suitable for continuous 24/7 data center operation.

Variants

The X24 ships in both SATA 6Gb/s and SAS 12Gb/s interfaces, each with multiple security options:

Option	Description
SATA	6Gb/s, standard in most homelab and NAS setups
SAS	12Gb/s dual-port, requires a SAS HBA or RAID controller
ISE	Instant Secure Erase for cryptographic drive disposal
SED	Self-Encrypting Drive with hardware-based full-disk encryption
SED-FIPS	FIPS 140-3 validated self-encryption (SAS only)

All models ship in 512e format with FastFormat support for converting to 4Kn. SAS models support 512e and 4Kn with variable sector sizes (512/520/528 and 4096/4160/4224).

Helium Design

Like all high-capacity Exos drives, the X24 uses a helium-sealed design with side-sealing weld technology. Helium's lower density reduces turbulence and drag on the platters, enabling more platters per enclosure while lowering power consumption. Idle power draw is 6.3W (SATA) or 6.5W (SAS), with operating power peaking at 8.9W (SATA) or 9.8W (SAS) under random read workloads.

PowerBalance and PowerChoice

PowerBalance technology optimizes the watts-per-terabyte ratio by allowing the drive to trade a small amount of sequential throughput for lower power consumption. PowerChoice provides multiple idle power states, letting the host system balance responsiveness against power savings based on workload patterns.

Reliability

Backed by a 2.5-million-hour MTBF, a 550TB/year workload rating, and a nonrecoverable read error rate of less than 1 in 10^15 bits. The 5-year limited warranty covers all models. Seagate Secure provides RSA 3072 firmware verification across the lineup.

Exos X24 vs. Exos 7E10

The 7E10 covers 2-10TB with a 256MB cache, 2-million-hour MTBF, and older recording technology. The X24 picks up at 12TB with a larger 512MB cache, higher MTBF, and Mozaic 3+ platters. For homelabbers needing more than 10TB per drive with enterprise reliability, the X24 is the current-generation choice.

Best for: High-density homelab storage, ZFS pools, TrueNAS builds, and anyone who wants enterprise-grade reliability at capacities above 10TB.

Avoid if: You only need small-capacity drives (10TB or under), or your budget favors NAS drives like the IronWolf Pro over enterprise pricing.