HP · ProLiant OEM
781518-B21 is HP ProLiant OEM 1.2TB SAS-12G. 2 of its 2 segments are defined in HP's published documentation and decoded below; for the rest we have not found a defining document, and they are marked as such. 1 live listing below.
| Segment | What it means | Source |
|---|---|---|
| 781518 | HPE part identifier. HPE publishes which product each number corresponds to; we have not found an HPE document giving a character-level grammar for this field. | HPE |
| B21 | Option part number - the orderable product as sold, typically including mounting hardware. | HPE |
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 HP - 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: HPE - spare part numbers and how to find them.
781518-B21 is HP ProLiant OEM, a 1.2TB 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, offered both new and refurbished (the table shows each listing's cheapest offer), and the two frequently carry different warranty positions even when the part number is identical. 10 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 | HP |
| Family | ProLiant OEM |
| Capacity | 1.2TB |
| Interface | SAS-12G |
| Product class | HDD |
These are the part numbers most often confused with 781518-B21. 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 | |
|---|---|---|---|---|
| 508011-001 | 1TB | SAS-6G | in catalogue | |
| 653959-001 | 3TB | SAS-6G | in catalogue | |
| 695510-B21 | 4TB | SAS-6G | in catalogue | |
| 695842-001 | 4TB | SAS-6G | in catalogue | |
| 781578-001 | 1.2TB | SAS-12G | in catalogue | |
| 791034-B21 | 1.8TB | SAS-12G | in catalogue | |
| 834031-B21 | 8TB | SAS-12G | in catalogue | |
| 846523-004 | 4TB | SAS-12G | in catalogue | |
| 861754-B21 | 6TB | SAS-12G | in catalogue | |
| 872745-001 | 4TB | SAS-12G | in catalogue |
Amber cells differ from 781518-B21; grey cells match it.
| Listing | Condition | Pack | $/TB | Price | |
|---|---|---|---|---|---|
| HP 781518-B21 1.2TB 12G SAS 10K | Refurb | single | $54.17 | $65.00 | Buy on Amazon |
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 HP 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 and interface, any part number · ranked by live cost per tb, refreshed about once a day
| Drive | Capacity | Interface | Recording | Condition | $/TB | Price | |
|---|---|---|---|---|---|---|---|
| HGST 1.2TB 10K SAS 12G 2.5 HUC101212CSS600 | 1.2TB | SAS-12G | — | REFURB | $44.17 | $53 | Buy on Amazon |
| HP 781578-001 1.2TB 12G SAS 10K 781578-001 | 1.2TB | SAS-12G | — | NEW | $45.83 | $55 | Buy on Amazon |
| Dell 36RH9 1.2TB 10K SAS 6G 36RH9 | 1.2TB | SAS-6G | — | NEW | $48.33 | $58 | Buy on Amazon |
| Dell 1.2TB 2.5 10K SAS 12G 89D42 | 1.2TB | SAS-12G | — | REFURB | $49.99 | $60 | Buy on Amazon |
Every 1.2TB drive we track, ranked by cost per terabyte.
Product pages for 781518-B21: HP 781518-B21 1.2TB 12G SAS 10K. Each carries that listing's own condition, provenance and alternatives; the priced table above is in-stock offers only.
781518-B21 is HP ProLiant OEM 1.2TB SAS-12G. 2 of its 2 segments are defined in HP'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.
The part number cannot tell you - coverage follows how the unit entered the market, not its designation. Of the 1 live listing we track for 781518-B21, 1 is sold new and the rest used or recertified, and only the new units can carry HP's own cover. Check the specific serial with the manufacturer before buying.
781518-B21 and 508011-001 are both in the ProLiant OEM range. The clearest difference is capacity - 1.2TB against 1TB. They differ in interface: SAS-12G against SAS-6G, which decides whether the drive fits your controller. 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; the cheapest sits under ASIN B00TOCV1SU. Prices come from Amazon US, re-checked about once a day per listing; the buy links go to the live listing because the price can change between our check and your click.