Samsung Memory Guide: Part Numbers, Speed Codes & Compatible Modules
Samsung memory part numbers encode the full module specification: type, DDR generation, capacity, rank and width, and speed. This guide shows how to read them, so you can match a module from a server label, a BMC inventory or a quote. To go straight to the products, shop Samsung part number cross-reference memory or type the part number into the search bar at the top of the page.
The structure of a Samsung part number
Take M321R8GA0PB0-CWM. M321 is the module type (RDIMM). R is the DDR generation: B is DDR3, A is DDR4 and R is DDR5. 8GA0 is the capacity and organization code (64GB, 2Rx4). PB0 is the die and board revision. -CWM is the speed (DDR5-5600). The same pattern applies to DDR4: in M393A4K40DB3-CWE, M393 is RDIMM, A is DDR4, 4K40 is 32GB 2Rx4, DB3 is the revision and -CWE is DDR4-3200.
Module type prefixes
| Module type | Typical use | DDR3 | DDR4 | DDR5 |
|---|---|---|---|---|
| ECC Registered (RDIMM) | rack and tower servers, workstations | M393B | M393A | M321R, M329R |
| ECC Registered, very low profile (VLP RDIMM) | blades and dense 1U systems | M392B | M392A | — |
| ECC Load-Reduced (LRDIMM) | high-capacity servers | M386B | M386A | — (DDR5 has no LRDIMM) |
| ECC Unbuffered (ECC UDIMM) | entry servers, workstations | M391B | M391A | M324R |
| Non-ECC Unbuffered (UDIMM) | desktops | M378B | M378A | M323R |
| ECC SODIMM | NAS, edge servers, compact systems | M474B | M474A | M426R |
| Non-ECC SODIMM | laptops, mini PCs | M471B | M471A | M425R |
Speed suffixes
| DDR5 suffix | Speed | DDR4 suffix | Speed | DDR3 suffix | Speed |
|---|---|---|---|---|---|
| -CQK, -CWK (3DS) | DDR5-4800 | -CPB, -CRB | DDR4-2133 | -CH9 / -YH9 | DDR3-1333 |
| -CWM | DDR5-5600 | -CRC, -CTC, -CUC | DDR4-2400 | -CK0 / -YK0 | DDR3-1600 |
| -CCP | DDR5-6400 | -CTD, -CWD | DDR4-2666 | -CMA / -YMA | DDR3-1866 |
| -CVF, -CYF (3DS) | DDR4-2933 | ||||
| -CWE, -CAE (3DS) | DDR4-3200 |
On DDR3 the first letter of the suffix gives the voltage: C is 1.5V and Y is 1.35V (DDR3L). (3DS) marks high-capacity stacked modules.
DDR5 capacity and organization codes
The four characters after the generation letter give capacity and organization. In DDR5, A0 means x4 DRAM, A3 means x8 and B4 means x16.
| Code after M321R / M324R / M426R… | Module | Example part |
|---|---|---|
| 1GB4 | 8GB 1Rx16 | M425R1GB4BB0-CQK |
| 2GA3 | 16GB 1Rx8 | M321R2GA3PB0-CWM |
| 4GA0 | 32GB 1Rx4 | M321R4GA0PB0-CWM |
| 4GA3 | 32GB 2Rx8 | M321R4GA3PB0-CWM |
| 6GA0 | 48GB 1Rx4 | M321R6GA0PB0-CWM |
| 6GA3 | 48GB 2Rx8 | M321R6GA3PB0-CWM |
| 8GA0 | 64GB 2Rx4 | M321R8GA0PB0-CWM |
| YGA0 | 96GB 2Rx4 | M321RYGA0PB0-CWM |
| AJA0 | 128GB 2Rx4 | M321RAJA0MB0-CWM |
| AGA0 | 128GB 4Rx4 (3DS) | M321RAGA0B20-CWK |
| BGA0 | 256GB 8Rx4 (3DS) | M321RBGA0B40-CWK |
DDR4 capacity and organization codes
In DDR4 the last two digits give the DRAM width: 40 is x4, 43 is x8 and 44 is x16. Where one code covers two organizations, the NEMIX RAM listing states the rank.
| Code after M393A / M391A / M471A… | Module | Example part |
|---|---|---|
| 5143 | 4GB 1Rx8 | M393A5143DB0-CRC |
| 5244 | 4GB 1Rx16 | M471A5244CB0-CWE |
| 1K43 | 8GB 1Rx8 | M393A1K43DB1-CWE |
| 1G43 | 8GB 2Rx8 | M393A1G43EB1-CRC |
| 1G40 | 8GB 1Rx4 | M393A1G40EB1-CRC |
| 2K43 | 16GB 2Rx8 | M393A2K43DB3-CWE |
| 2G43 | 16GB 1Rx8 | M391A2G43BB2-CWE |
| 2K40 | 16GB 1Rx4 | M393A2K40DB3-CWE |
| 2G40 | 16GB 2Rx4 | M393A2G40EB2-CTD |
| 4G43 | 32GB 2Rx8 | M393A4G43AB3-CWE |
| 4K40 | 32GB 2Rx4 | M393A4K40DB3-CWE |
| 4G40 | 32GB 1Rx4 (RDIMM); 32GB 4Rx4 on older M386 LRDIMMs | M393A4G40AB3-CWE |
| 8G40 | 64GB 2Rx4 | M393A8G40AB2-CWE |
| 8K40 | 64GB 4Rx4 (LRDIMM or 3DS) | M386A8K40DM2-CWE |
| AG40 | 128GB 4Rx4 | M386AAG40BM3-CWE |
| AK40 | 128GB 8Rx4 | M393AAK40B42-CWD |
| BG40 | 256GB 8Rx4 (3DS) | M393ABG40M52-CAE |
What the revision letters mean
The characters before the dash (for example DB3, EB2, PB0 or BB0) track Samsung's DRAM die and board revisions. They change when Samsung moves a module to newer silicon, but the server reads only generation, type, capacity, rank, width and speed. A module with the same prefix, capacity code and speed suffix is the same to the system, whatever the revision.
Where you will find the number
- On the module label. Server makers including Dell, HPE, Lenovo, Cisco and Supermicro often ship Samsung modules; the Samsung number usually appears on the label beside or under the server maker's own part number.
- In the BMC inventory (iDRAC, iLO, XClarity, CIMC or IPMI). A slot holding a Samsung module lists its Samsung part number.
- In a quote or configurator bill of materials. Resellers often quote Samsung numbers.
Compatible module or Samsung original?
The cross-reference collection lists NEMIX RAM modules matched to each Samsung number on every attribute the memory controller reads. Every module is researched, matched, and compatibility-tested by NEMIX RAM, a US-based server memory specialist since 1993, and backed by a lifetime warranty. Where a qualified vendor list or procurement specification requires the Samsung-branded part, see Samsung Original memory modules, available on request for a quote.
Shop by module type
- DDR5 RDIMM and DDR4 RDIMM for servers
- DDR4 LRDIMM for high-capacity servers
- ECC UDIMM for entry servers and workstations
- ECC SODIMM for NAS and edge systems
Other memory makers: the SK hynix memory part number guide and the Micron memory part number guide.
Buying for a fleet
Purchase orders, net terms and volume pricing are available for data centers, research labs, universities, government buyers and resellers. Send Samsung part numbers with quantities, or a BMC inventory export, and we will return a matched set. Request a quote.
Frequently asked
My part number is not listed.
Check the prefix, capacity code and speed suffix against the tables above; a listing that matches all three is the same module. If nothing matches, send us the number and we will confirm the right module.
Is M329R different from M321R?
Both are DDR5 RDIMMs. Match the capacity code and speed suffix as listed.
Does a faster module work in a slower server?
Yes. Memory runs at the speed the processor and population support, so a DDR4-3200 (-CWE) module runs at DDR4-2933 in a 2nd Gen Xeon Scalable server.
Can RDIMM and LRDIMM be mixed?
No. M393 (RDIMM) and M386 (LRDIMM) modules cannot be installed in the same server.
NEMIX RAM can deliver any Configuration your Fleet Requires
Speak to a Sales Representative