Samsung · Samsung DDR4 RDIMM
M393A8G40BB4-CWE is Samsung Samsung DDR4 RDIMM 64GB DDR4-3200. 2 of its 4 segments are defined in Samsung's published documentation and decoded below; the rest are not publicly documented and are marked as such. No live listings right now - the reference material below still applies.
| Segment | What it means | Source |
|---|---|---|
| M | Samsung memory module prefix. | Samsung |
| 393 | DDR4 Registered DIMM (RDIMM). | Samsung |
| A8G40BB4 | Not sourced - Samsung does not publicly document this segment. | Not sourced |
| CWE | Not sourced - Samsung does not publicly document 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 Samsung - 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: Samsung - DDR4/DDR5 module part-number decoder.
M393A8G40BB4-CWE is Samsung Samsung DDR4 RDIMM, a 64GB server memory module on DDR4-3200. Registered ECC modules are not interchangeable with unbuffered desktop memory, and a server board will generally refuse to post with the wrong type rather than run slowly.
We hold no live listing against this exact part number at the moment. 5 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 | Samsung |
| Family | Samsung DDR4 RDIMM |
| Capacity | 64GB |
| Interface | DDR4-3200 |
| Product class | RAM |
These are the part numbers most often confused with M393A8G40BB4-CWE. 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 | |
|---|---|---|---|---|
| M393A2G40EB1-CPB | 16GB | DDR4-2133 | in catalogue | |
| M393A4K40CB1-CRC | 32GB | DDR4-2400 | in catalogue | |
| M393A4K40CB2-CTD | 32GB | DDR4-2666 | in catalogue | |
| M393A8G40AB2-CWE | 64GB | DDR4-3200 | in catalogue | |
| M393A8K40B22-CWD | 64GB | DDR4-2666 | in catalogue |
Amber cells differ from M393A8G40BB4-CWE; grey cells match it.
No seller we track has M393A8G40BB4-CWE 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 Samsung memory support. We link the tool rather than showing a result here, because the answer depends on the individual drive and only Samsung 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 gb, refreshed about once a day
| Drive | Capacity | Condition | $/GB | Price | |
|---|---|---|---|---|---|
| SK Hynix 64GB DDR4-2400 ECC RDIMM HMAA8GL7MMR4N | 64GB | REFURB This offer: sold by Advanced Technology Recycling · Amazon says Used / VeryGood | $4.61 | $295 | Buy/View Price |
| Supermicro 64GB DDR4-2666 ECC LRDIMM B07DFLTWN3 | 64GB | NEW This offer: sold by Aventis Systems · Amazon says New / Unknown | $6.23 | $399 | Buy/View Price |
| Samsung 64GB DDR4-2666 ECC RDIMM M393A8K40B22-CWD | 64GB | NEW This offer: sold by Aventis Systems · Amazon says New / Unknown | $6.23 | $399 | Buy/View Price |
| SK Hynix 64GB DDR4-3200 ECC RDIMM HMAA8GR7AJR4N-XN | 64GB | NEW This offer: sold by Memorybank · Amazon says New / Unknown | $9.36 | $599 | Buy/View Price |
M393A8G40BB4-CWE is Samsung Samsung DDR4 RDIMM 64GB DDR4-3200. 2 of its 4 segments are defined in Samsung'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 Samsung's own tool, linked in the warranty section on this page.
Both are in the Samsung DDR4 RDIMM range. The clearest difference is capacity - 64GB against 16GB. They differ in interface: DDR4-3200 against DDR4-2133, which decides whether the drive fits your controller. 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 M393A8G40BB4-CWE 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.