One server part can carry four or five different numbers: an option kit number for ordering, a spare number for service, an assembly number, and the original maker's model number. Knowing which is which is the fastest way to get the right part and a fast, accurate quote.
Why one part has several numbers
Server manufacturers do not make most of their own drives, memory or power supplies. They buy them from component makers, test them, load their own firmware and labels, and sell them under their own numbers. Each stage in that chain adds a number:
| Number type | Who uses it | What it identifies |
|---|---|---|
| Option or kit number | Buyers, resellers | The boxed part you order as an upgrade, often with carrier, cables or a heatsink |
| Spare or FRU number | Service engineers | The replacement part sent when a part fails under support |
| Assembly or board number | Factory, repair | A specific build or revision of the part |
| OEM model number | Component maker | The underlying drive, memory module or chip, e.g. a Seagate or Samsung model |
| Superseded or replacement number | Everyone | A newer number that replaces an older one for the same function |
Two parts with the same OEM model number are not always interchangeable. The server brand's firmware, carrier and validation can differ. Always match the server brand's own number when the system expects branded parts.
HPE: option kits (-B21) and spares (-001)
HPE uses a clear suffix pattern.
- Option kit numbers usually end in -B21, for example the format
123456-B21orP12345-B21. This is the number on the box and on HPE's QuickSpecs. A few product types use other suffixes, such as some processor kits. - Spare part numbers usually end in -001 (sometimes -002 or higher for later revisions), for example
123456-001. This is the number HPE service uses for replacements. - Assembly numbers appear on many labels as well. They identify the build and are useful when two spares look alike.
- CTO and factory options for configure-to-order servers may carry their own codes that do not appear on the part itself.
An HPE drive label often shows the option number, the spare number, the assembly number and the drive maker's model number together. Give us any of them. Our search matches option, spare and alternative numbers listed on each product page.
Lenovo: option numbers and FRU numbers
Lenovo ThinkSystem and older System x parts carry two main numbers.
- Option part numbers are what you order as an upgrade. On ThinkSystem, many start with 4X or 7X, followed by a mix of digits and letters.
- FRU numbers (field replaceable unit) are 7-character numbers such as the format
01AB123. Lenovo service uses them for replacements. - CRU numbers (customer replaceable unit) follow the same format, for parts the customer can swap without an engineer.
- Feature codes are 4-character codes used in Lenovo configuration tools. They identify an option inside a configured system.
Parts from the IBM System x era often keep their IBM-style FRU numbers after the move to Lenovo, so the same part can appear under both brand names.
Dell: part numbers, PPID labels and SKUs
Dell uses a different scheme.
- Dell part number (DPN) is a 5-character alphanumeric code, such as the format
0AB12Cwhen shown with its leading zero. This is the number that identifies the physical part. - PPID label (Piece Part Identification) is the sticker on Dell parts. It reads like
CN-0AB12C-12345-...: country of origin, the part number, then supplier and date codes. The part number is the block after the country code. - Dell SKU numbers use a
NNN-AAAAformat, such as400-XXXXfor many drives or370-XXXXfor many memory modules. They are sales codes and can map to more than one physical part number over time.
When you send a Dell request, the 5-character part number from the PPID label is the most precise reference.
Cisco: product IDs
Cisco orders by product ID (PID), a readable code such as a model name with speed or capacity in it. Spare PIDs ordered on their own usually end in =, while the same part ordered inside a system has no equals sign. Cisco parts also carry a separate top assembly number (TAN) and a version ID on the label, which help identify hardware revisions.
Superseded and replacement numbers
Manufacturers retire part numbers and replace them with new ones, often when a component maker changes or a firmware revision is required. The new number is described as the replacement, and the old one as superseded. In most cases the replacement works in the same systems, but check the manufacturer's support matrix for older platforms. Product pages on this site list superseded and replacement numbers where we have them, with links in both directions.
Where to find the number
- Drives: the label on the drive body, and sometimes a second label on the carrier.
- Memory: a sticker on one side of the module. Look for the brand's spare or option number and the module maker's part number.
- Power supplies: the label on the top or side of the unit.
- Boards and controllers: a sticker near the edge of the board, often with a barcode.
- In the system: management tools such as HPE iLO, Dell iDRAC and Lenovo XClarity list installed parts, often with part numbers and serials.
- Documentation: HPE QuickSpecs, Lenovo Press product guides and Dell documentation list option numbers per server model.
How to use this when you buy
- Send the number printed on your existing part, whichever type it is.
- If you have several numbers from the same label, send all of them.
- Add the server model and generation so the part can be checked for fit.
- Search the catalog by part number, or send it through Source a Part if it is not listed.
See also our server catalog, server memory and storage drives. Ready to buy? Build an RFQ.