WD · Ultrastar HC520
HUH721212AL5204 is WD Ultrastar HC520 12TB SAS-12G. 2 of its 4 segments are defined in WD's published documentation and decoded below; the rest are not publicly documented and are marked as such. 1 live listing below.
| Segment | What it means | Source |
|---|---|---|
| HUH | Ultrastar He series, helium-filled (earlier branding). | Western Digital |
| 721212 | Capacity and generation field. The leading digits encode capacity in the family's own scheme; see the specification sheet linked below for the exact model. | Western Digital |
| AL | WD does not publicly document this segment. | not documented |
| 5204 | WD does not publicly document this segment. | not documented |
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 WD - 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.
HUH721212AL5204 is WD Ultrastar HC520, a 12TB 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 currently track 1 live listing against this exact part number, all of it refurbished or recertified stock. 2 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 | WD |
| Family | Ultrastar HC520 |
| Capacity | 12TB |
| Interface | SAS-12G |
| Product class | HDD |
These are the part numbers most often confused with HUH721212AL5204. 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 | |
|---|---|---|---|---|
| HUH721212AL5200 | 12TB | SAS-12G | in catalogue | |
| HUH721212AL5205 | 12TB | SAS-12G | in catalogue |
Amber cells differ from HUH721212AL5204; grey cells match it.
| Listing | Condition | Pack | $/TB | Price | |
|---|---|---|---|---|---|
| WD Ultrastar 12TB SAS HUH721212AL5204 | Refurb | single | $26.58 | $319.00 | Buy |
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 and check it with WD directly before buying. We do not link a checker for this manufacturer because we have not verified one.
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, any part number · ranked by live cost per tb, refreshed every few hours
| Drive | Capacity | Interface | Recording | Condition | $/TB | Price | |
|---|---|---|---|---|---|---|---|
| WD Ultrastar 12TB SAS HUH721212AL5204 HUH721212AL5204 | 12TB | SAS-12G | CMR | REFURB | $26.58 | $319 | Buy |
| WD Ultrastar 12TB SAS HUH721212AL5205 HUH721212AL5205 | 12TB | SAS-12G | CMR | REFURB | $27.42 | $329 | Buy |
| MDD 12TB SATA 6G 7200RPM Enterprise MDD12TSATA25672E | 12TB | SATA-6G | CMR | REFURB | $27.50 | $330 | Buy |
| WD Ultrastar 12TB SAS HUH721212AL4200 HUH721212AL4200 | 12TB | SAS-12G | CMR | REFURB | $27.74 | $333 | Buy |
Every 12TB drive we track, ranked by cost per terabyte.
HUH721212AL5204 is WD Ultrastar HC520 12TB SAS-12G. 2 of its 4 segments are defined in WD's own published documentation - the decode table on this page shows each one with the document that defines it. The remaining segments are not publicly documented, 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 the manufacturer before buying.
Both are in the Ultrastar HC520 range. The variant table on this page lists every sibling we document with what differs.
We track 1 live listing carrying this part number, shown above with condition and cost per terabyte. Prices come from Amazon US and are re-checked continuously; the buy links go to the live listing because the price can change between our check and your click.
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.