The Seagate Exos 25TB covered here is the ST25000NM000E Exos Xz model, not a generic 25TB capacity listing. It sits in an unusual place: one terabyte above conventional 24TB enterprise drives, but with host-managed SMR behavior that makes the architecture more important than the capacity number.
That means the buying decision is not simply whether 25TB is larger than 24TB. It is whether your host, filesystem, controller path and workload are designed for a ZAC host-managed zoned device. If not, a 24TB CMR Exos X24 or a newer CMR Exos capacity is usually the cleaner purchase.
The Seagate Exos 25TB ST25000NM000E is a 25TB SATA enterprise HDD in the Exos Xz support family, with SMR/ZAC host-managed zoned behavior. Buy it only for storage stacks that can manage host-managed SMR correctly. For conventional NAS, hardware RAID, unqualified ZFS or mixed random-write storage, use a CMR Exos model instead.
Manufacturer-published values for the exact product family. Retail listings can collapse these details, so match the part number before ordering.
| Spec | Value |
|---|---|
| Model number | ST25000NM000E |
| Capacity | 25TB decimal marketed capacity |
| Recording technology | SMR / ZAC host-managed zoned device |
| Platform | Seagate Exos Xz 25TB SATA SMR platform; public Seagate records also expose the same part number in Exos X22 firmware context |
| Interface | SATA 6Gb/s, single port |
| Sector format | FastFormat 512e/4Kn family; product manual lists 512-byte logical and 4096-byte physical sectors |
| Spindle speed | 7200 RPM |
| Cache / buffer | 512MB |
| Maximum sustained transfer rate | 260MB/s maximum sustained transfer rate, outer diameter |
| Workload rating | <550TB/year |
| Reliability rating | 2.5M hours; 0.35% annualized failure rate class |
| Warranty | 5-year limited warranty |
| Power | 6.7W idle average; 10W maximum operating in published data-sheet table |
| Acoustics | 2.8 Bels idle typical; 3.4 Bels seek maximum |
| Operating temperature | 10C to 60C operating |
| Compatibility note | Requires a host and storage stack that can use ZAC host-managed SMR correctly; not a generic CMR replacement. |
No exact in-stock live row is currently matched for ST25000NM000E. Relevant live alternatives are shown so the page does not collapse into an empty catalogue.
Live prices · updated every 4-5 hours · last checked 7 hr ago · exact model not currently matched in live stock
| Model | Capacity | Recording | RPM | Workload TB/yr | Warranty | $/TB | Price | |
|---|---|---|---|---|---|---|---|---|
| 24TB ST24000NM002HREFURB | 24TB | CMR | 7,200 | 550 | 5 yr | $29.17 | $700 | Buy |
| 24TB ST24000NM000H | 24TB | CMR | 7,200 | 550 | 5 yr | $58.37 | $1401 | Buy |
Workload rating is recorded per part number from Seagate's datasheet for that exact model, not blanketed across the line — two drives of the same capacity can differ because they are different generations. A dash means the figure is not stated for that listing. Recording technology comes from the manufacturer's published CMR/SMR list; a model absent from that list is shown as UNVERIFIED rather than guessed. Rows priced above 3× this line's in-stock median are flagged and excluded from the winner callout and from every median we compute.
This table is computed from live DatacenterDisk rows when an exact in-stock match exists. It is intentionally blank for unavailable models rather than filled with stale prices.
| Live model | Drive price | $/TB | 100TB raw target | 500TB raw target | 1PB raw target |
|---|---|---|---|---|---|
| No exact in-stock row is available right now. Use the availability table for nearby live alternatives, then re-check the exact model before ordering. | |||||
Raw capacity is not usable capacity. This table shows the slot-level math before filesystem overhead, snapshots, reserved space and vendor-specific parity layouts.
| Drive count | Raw capacity | Single-parity usable | Dual-parity usable |
|---|---|---|---|
| 4 bays | 100TB | 75TB | 50TB |
| 6 bays | 150TB | 125TB | 100TB |
| 8 bays | 200TB | 175TB | 150TB |
| 12 bays | 300TB | 275TB | 250TB |
The raw capacity gain is easy to calculate. The harder question is whether that 4.2 percent gain is enough to justify a different recording model.
| Deployment | 24TB raw | 25TB raw | Extra raw capacity |
|---|---|---|---|
| 8 drives | 192TB | 200TB | 8TB |
| 12 drives | 288TB | 300TB | 12TB |
| 24 drives | 576TB | 600TB | 24TB |
| 60 drives | 1440TB | 1500TB | 60TB |
A 25TB enterprise HDD exists because data-center buyers often value every extra terabyte per slot. In a rack full of drives, one extra TB per bay becomes a meaningful number. In a 60-drive shelf, the jump from 24TB to 25TB adds 60TB raw before parity, erasure coding and reserved capacity.
The trap is assuming this is a simple CMR step above 24TB. Seagate's Exos Xz data sheet and product manual identify ST25000NM000E as an SMR/ZAC host-managed zoned device. That is a different operational class from conventional Exos X24 CMR models.
A host-managed SMR drive expects the host to respect zoned-write rules. Software has to place and sequence writes deliberately. Storage layers that hide the drive behind a generic random-write block abstraction can defeat the benefit or make the drive unusable for the intended workload.
This is why ST25000NM000E should not be marketed internally as a casual NAS upgrade. It can be appropriate for sequential ingest, bulk retention and purpose-built object storage. It is a poor fit for random-write file shares, VM datastores and controllers that do not expose the needed semantics.
The capacity gain over 24TB is about 4.2 percent per drive. That can be valuable at scale, but it is too small to ignore engineering work. A conventional 24TB Exos X24 can be cheaper in total cost if it avoids validation, host changes and operational restrictions.
Use live price per TB as the first screen, then multiply by the array. If exact ST25000NM000E stock is unavailable, the alternatives shown on this page are pricing context rather than substitutes for the same architecture.
The Exos 25TB ST25000NM000E is a procurement-specific storage part for buyers who know they need the 25TB host-managed SMR branch. It is not the default Seagate enterprise recommendation for normal servers.
If you cannot name the host-managed SMR layer in your storage stack, the safer answer is a CMR Exos model and a conventional compatibility check.
ST25000NM000E is Seagate's 25TB Exos Xz SATA model covered here.
Seagate's Exos Xz documentation identifies this 25TB model as SMR and the product manual describes ZAC host-managed zoned behavior.
Not as a default recommendation. Use it only when the NAS or storage software explicitly supports the host-managed SMR behavior of the exact model.
No. Price per TB is the first screen, not the whole decision. Match recording method, interface, bay count, firmware support, warranty position and rebuild risk before accepting the cheapest row.
Specification claims on this page were checked against the pages below on 1 September 2026. Where a widely-repeated figure did not survive that check, we report what the source says now and say so in the text rather than repeating the familiar number.