HGST · Ultrastar
HUS724040ALS640 is HGST Ultrastar SAS-12G. 3 of its 4 segments are defined in HGST's published documentation and decoded below; for the rest we have not found a defining document, and they are marked as such. No live listings right now - the reference material below still applies.
| Segment | What it means | Source |
|---|---|---|
| HUS | Ultrastar enterprise series, air-filled. | Western Digital |
| 724040 | Capacity and generation field. The leading digits encode capacity in the family's own scheme; each model's own specification sheet states its exact capacity. | Western Digital |
| ALS | SAS interface. | Western Digital |
| 640 | Not sourced - we have not found a HGST document defining this segment. | Not sourced |
We decode only what the manufacturer documents. There is a large body of community knowledge about the undocumented segments above, much of it probably right, and none of it published by HGST - so it does not appear in this table. A reading nobody can check does not belong in a column headed “what it means”. Grammar reference: Western Digital - Ultrastar model-number nomenclature.
HUS724040ALS640 is HGST Ultrastar, a hard drive on SAS-12G. Being a SAS device, it needs a SAS host bus adapter or backplane - it will not run from a motherboard SATA port, though a SATA drive will run on a SAS controller.
We hold no live listing against this exact part number at the moment. 11 sibling part numbers are documented below - these are the numbers most often mistaken for this one, and the table marks which fields actually differ.
| Manufacturer | HGST |
| Family | Ultrastar |
| Interface | SAS-12G |
| Product class | HDD |
These are the part numbers most often confused with HUS724040ALS640. The differences below come from the same vendor documentation as the decode above - where a field is not documented, the row leaves it blank rather than guessing.
| Part number | Capacity | Interface | Format | |
|---|---|---|---|---|
| HUC101212CSS600 | SAS-12G | in catalogue | ||
| HUS723030ALS640 | SAS-6G | in catalogue | ||
| HUS724030ALA640 | SATA-6G | in catalogue | ||
| HUS724030ALS640 | SAS-6G | in catalogue | ||
| HUS726040ALS210 | 4TB | SAS-12G | in catalogue | |
| HUS726060AL5210 | 6TB | SAS-12G | in catalogue | |
| HUS726060ALS641 | SAS-6G | in catalogue | ||
| WUH722014CLE6L4 | SATA-6G | in catalogue | ||
| WUH722020CLE6L4 | SATA-6G | in catalogue | ||
| WUH722624ALE6L4 | SATA-6G | in catalogue | ||
| WUS721204BLE6L4 | SATA-6G | in catalogue |
Amber cells differ from HUS724040ALS640; grey cells match it.
No seller we track has HUS724040ALS640 in stock right now. That describes today's listings only - it says nothing about whether the model is discontinued. We are not going to fill this space with something else and call it a match. The decode, specifications and sibling table above are the reference answer for this part number and remain accurate whether or not anyone is selling one today. If you need the capacity rather than this specific part, the alternatives below are what is actually buyable.
A manufacturer part number does not imply a manufacturer warranty, and this is where part-number buyers lose the most money. OEM stock, integrator pulls and gray-market units all reach the market under the maker's own numbering. Retailers selling them sometimes state plainly that the manufacturer warranty is none; others simply do not mention it, which is not the same as it being covered.
Coverage attaches to the individual unit and its serial number, not to the part number. That means the only reliable answer comes from the manufacturer, about the specific drive you are being sold.
Ask the seller for the serial number before purchase, then enter it in Western Digital warranty checker. We link the tool rather than showing a result here, because the answer depends on the individual drive and only Western Digital can give it.
A seller warranty is a different promise from a different company. What each warranty tier actually covers · Verify on arrival
4 in-stock listings · same capacity and interface, any part number · ranked by live cost per tb, refreshed about once a day
| Drive | Capacity | Interface | Recording | Condition | $/TB | Price | |
|---|---|---|---|---|---|---|---|
| HGST HUS726040ALS210 4TB SAS 12G HUS726040ALS210 | 4TB | SAS-12G | — | REFURB This offer: sold by CA Tech Depot · Amazon says Used / VeryGood | $12.50 | $50 | Buy/View Price |
| HP 695842-001 4TB SAS 6G 695842-001 | 4TB | SAS-6G | — | NEW This offer: sold by Computer Supply · Amazon says New / New | $17.00 | $68 | Buy/View Price |
| Dell 012GYY 4TB SAS 6G Renewed 012GYY | 4TB | SAS-6G | — | REFURB This offer: sold by Computer Supply · Amazon says New / New · title says Renewed | $21.25 | $85 | Buy/View Price |
| Dell DRMYH Compellent 4TB NL SAS Renewed DRMYH | 4TB | SAS-6G | — | REFURB This offer: sold by Redefine IT · Amazon says New / New · title says Renewed | $22.50 | $90 | Buy/View Price |
Every drive we track, ranked by cost per terabyte.
HUS724040ALS640 is HGST Ultrastar SAS-12G. 3 of its 4 segments are defined in HGST's own published documentation - the decode table on this page shows each one with the document that defines it. For the remaining segments we have not found a defining document, and we say so rather than repeating a community guess as fact.
Not necessarily, and the part number cannot tell you. Coverage depends on how the individual unit entered the market and whether it was registered, not on its model designation. OEM and gray-market stock reaches the market under manufacturer part numbers regularly and frequently carries no manufacturer warranty at all - some retailers print exactly that on the listing. Check the specific serial with HGST's own tool, linked in the warranty section on this page.
Both are in the Ultrastar range. The variant table on this page lists every sibling we document with what differs.
We hold no live listing for this part number right now. That is the honest state rather than a broken page - this remains the reference answer for what HUS724040ALS640 is, how it decodes and which siblings it is confused with. The alternatives section below shows what is currently buyable at the same capacity.
Because more than one organisation names it. The manufacturer assigns a model number describing the product; a server vendor buying it in volume assigns its own spare-part number for its service catalogue; distributors sometimes add another. All identify the same physical drive, which is why one number returns listings that look like a different product. Our part number index explains the pattern per vendor.