Seagate Exos M - 3.5" Enterprise HDD - 30TB SATA ISE

The Exos M is Seagate's highest-capacity enterprise hard drive line, built on the Mozaic 3+ recording platform. Current models range from 24TB to 32TB using HEAT-assisted magnetic recording (HAMR) with 3TB-per-platter areal density. A 36TB model is also listed but not yet widely available.

Enterprise Specs

7,200 RPM, 512MB cache, CMR recording, SATA 6Gb/s interface. MTBF is 2.5 million hours with a 5-year warranty. Helium-sealed with rotational vibration sensors. Rated for 24/7 operation.

Sustained transfer rates range from 240 MB/s (24TB) to 285 MB/s (32TB). Idle power is 6.9W across all capacities.

Mozaic 3+ Platform

The Mozaic platform uses HAMR technology, where a tiny laser heats each bit location on the platter surface before writing. This allows data to be written at much higher densities than conventional PMR or EAMR methods. The result is 3TB per platter, which is how Seagate reaches 32TB in a standard 3.5" form factor with a helium-sealed design.

Homelab Relevance

The Exos M is Seagate's current-generation flagship. At retail pricing, the cost per terabyte is higher than older Exos X or WD Ultrastar models. For homelabbers, these drives make sense when maximum capacity per bay is the priority and you have the budget for current-gen hardware. In a 4-bay NAS, four 32TB Exos M drives in a mirrored or parity configuration give you storage density that would have required 8+ bays a generation ago.

These drives are too new to appear on the used market in significant volume. For budget builds, the Exos 7E10 or older Exos X-series drives offer much better value per terabyte on the used market.

Best for: High-density storage builds where maximizing terabytes per bay justifies paying current-gen retail pricing.

Avoid if: You are building on a budget. Older enterprise drives offer dramatically better cost per terabyte on the used market.