Synology HAT5320-24T versus WD Ultrastar HC590 is not just a 24TB-versus-26TB comparison. It is a support and qualification decision.
HAT5320 gives first-party Synology integration and compatibility-list clarity where the exact model is supported. HC590 gives a broader Western Digital enterprise CMR platform with 26TB density and SATA/SAS variants, but Synology support depends on the exact NAS model and policy bucket.
Choose Synology HAT5320-24T when the Synology system's compatibility list, DSM firmware workflow or support policy makes first-party drives valuable. Choose Ultrastar HC590 when the system explicitly supports third-party enterprise HDDs and the 26TB CMR capacity or live $/TB advantage outweighs the Synology qualification premium.
Use this as the procurement-level screen before looking at live price rows.
| Decision point | HAT5320 24TB | Ultrastar HC590 26TB |
|---|---|---|
| Capacity | 24TB | 26TB |
| Recording | CMR in product-spec/channel data | CMR/ePMR |
| Primary model | HAT5320-24T | WUH722626 family |
| Interface | SATA 6Gb/s | SATA 6Gb/s and SAS 12Gb/s variants |
| Max sustained transfer | 309MB/s typical | 302MB/s on 26TB variants |
| Workload / warranty | 550TB/year / 5 years | 550TB/year / 5 years |
| Best environment | Synology systems needing first-party qualification | General enterprise storage and Synology systems that accept the exact third-party model |
| Primary advantage | DSM firmware/support integration | +2TB per bay and broader enterprise channel |
| Main limitation | Higher $/TB risk and Synology-only value | Not automatically supported in every Synology model |
This shows the capacity delta only. The financial answer comes from the live $/TB rows on the page.
| Drive count | HAT5320 24TB raw | Ultrastar HC590 26TB raw | Raw delta |
|---|---|---|---|
| 4 bays | 96TB | 104TB | 8TB |
| 6 bays | 144TB | 156TB | 12TB |
| 8 bays | 192TB | 208TB | 16TB |
| 12 bays | 288TB | 312TB | 24TB |
HC590's extra 2TB per bay only matters if the Synology system and support plan permit the drive.
| Drive count | HAT5320 raw | HC590 raw | HC590 raw gain |
|---|---|---|---|
| 4 drives | 96TB | 104TB | 8TB |
| 8 drives | 192TB | 208TB | 16TB |
| 12 drives | 288TB | 312TB | 24TB |
| 24 drives | 576TB | 624TB | 48TB |
No exact in-stock live row is currently matched for HAT5320-24T / WUH722626ALE6L4. Relevant live alternatives are shown so the page does not collapse into an empty catalogue.
Live prices · updated every 4-5 hours · last checked 8 hr ago · one side may be unavailable in exact live stock
| Model | Capacity | Recording | RPM | Workload TB/yr | Warranty | $/TB | Price | |
|---|---|---|---|---|---|---|---|---|
| Ultrastar 20TB SATAREFURB | 20TB | CMR | 7,200 | — | — | $27.50 | $550 | Buy |
| 20TB WUH722020CLE6L4 | 20TB | CMR | — | — | — | $49.92 | $998 | 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. | |||||
HAT5320 asks the buyer to pay for Synology qualification and DSM integration. HC590 asks the buyer to accept a third-party enterprise drive in exchange for more capacity per bay and, often, a stronger general enterprise procurement market.
Neither answer is universally right. If support clarity is worth more than the capacity delta, HAT5320 is rational. If the Synology model allows the exact Ultrastar and the live $/TB gap is large, HC590 can be the better engineering and financial choice.
Synology's 2025+ drive rules vary by product series. The existing policy data on DatacenterDisk distinguishes DiskStation Plus from Value/J, RS Plus and enterprise classes. Some third-party HDD cases are allowed for new pools, some are migration-only, and some are not supported.
That means a statement such as third-party drives are always unsupported is wrong. So is a statement that any third-party enterprise drive is fine. The buyer has to check the exact Synology model, launch-year policy and compatibility list.
HC590 adds 2TB per bay over HAT5320-24T. In eight drives that is 16TB raw; in twenty-four drives it is 48TB raw. If bays are scarce and support permits HC590, that can matter.
The live product table should decide price cases. If exact HAT5320-24T is unavailable, older HAT rows are only Synology-family context. If exact HC590 is unavailable, adjacent Ultrastar rows are only enterprise-market context.
Synology's first-party drive pitch includes firmware handling through DSM and deep system validation. For small IT teams, that can be worth paying for because support escalation and firmware tracking are easier.
HC590 is a strong enterprise drive, but firmware and qualification happen through the drive vendor and system compatibility path rather than Synology's first-party drive channel. That is not a defect; it is a different operating model.
Buy HAT5320-24T when the system is a Synology appliance where first-party qualification and support simplicity are part of the purchase. Buy HC590 when the system explicitly supports the drive and the extra 2TB per bay or lower live $/TB is more valuable than first-party integration.
For unsupported Synology systems, do not force HC590 into the design just because it is CMR. For non-Synology systems, do not pay a Synology drive premium unless there is a clear operational reason.
It is better when first-party Synology qualification and DSM firmware handling matter. HC590 can be better where the exact Synology model supports it and price or 26TB density matters more.
Yes. HC590 is 26TB in this comparison, while HAT5320-24T is 24TB. The gain is 2TB per bay.
No. Synology policy varies by model series and launch year. Check the exact compatibility list and policy for the system.
Yes. Western Digital's HC590 26TB family is CMR/ePMR and does not carry the host-managed SMR restrictions of HC680 or HC690.
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.