Samsung M393A8G40BB4-CWE

Technical Overview

Samsung M393A8G40BB4-CWE is a 64GB DDR4-3200 RDIMM with a 2Rx4 organization and ECC. The module name is PC4-25600R. Samsung builds both the DRAM and the finished server module.

Most requests start from the number on the label, or from a build that needs 64GB DDR4-3200 RDIMM 2Rx4. Send the exact part number when you have it. If you only know the specification, send capacity, speed, module type and rank.

How to Read This Part Number

• M393A — Samsung DDR4 RDIMM family
• 8G40 — 64GB module density
• BB4 — die and package revision
• CWE — DDR4-3200 speed grade

Use the full code on the quote. Nearby AB2 codes share the same density class but use a different die revision.

Key Specifications

Part Number: M393A8G40BB4-CWE
Manufacturer: Samsung
Capacity: 64GB (1x 64GB)
Memory Type: DDR4 SDRAM
Module Type: RDIMM (Registered DIMM)
Speed: 3200 MT/s
Module Name: PC4-25600R
Rank / Organization: 2Rx4
Error Correction: ECC
Voltage: 1.2V
Pin Count: 288-pin
Form Factor: Standard-height DIMM

Before adding memory to a populated server, match these values against the modules already installed: capacity, DDR generation, RDIMM or LRDIMM, rank, organization, speed and voltage. Also confirm the server CPU and motherboard list 64GB 2Rx4 RDIMM as supported.

RDIMM vs LRDIMM

This module is an RDIMM. Mixing RDIMM and LRDIMM in the same population is usually not allowed. If the installed memory is LRDIMM (for example M386A), quote an LRDIMM equivalent, or send a photo of the current label.

Where This Module Is Used

• Replacing the same Samsung 64GB DDR4 RDIMM already in the server
• Capacity upgrades that specify 64GB DDR4-3200 RDIMM, 2Rx4
• Balanced server builds and spare stock that call out this exact code

The same Samsung module may also appear under an HPE, Dell, Cisco, Supermicro or Lenovo label. If you need the OEM-labeled stick, include that number on the quote as well.

Matching Related Modules

A different speed, rank, density, or RDIMM vs LRDIMM code is a different product. Before approving a substitute, match:

• 64GB
• DDR4-3200 / PC4-25600R
• RDIMM
• 2Rx4
• ECC
• 1.2V / 288-pin

Do not treat a 64GB 2Rx8 module, a DDR4-2666/2933 8G40 part, or an LRDIMM as a drop-in for this CWE 2Rx4 stick. If the label shows AB2 instead of BB4, send that exact code.

What to Send for a Quote

1. Part number: M393A8G40BB4-CWE
2. Quantity
3. Optional: server brand and model
4. Optional: photo of the module label
5. Or: 64GB + DDR4-3200 + RDIMM + 2Rx4

Mixed lists are fine, including other DDR4/DDR5 lines and OEM-labeled pulled memory.

FAQ

Is this an LRDIMM?
No. It is a Samsung DDR4 RDIMM (M393A). Confirm the installed type before ordering.

Is this the same as M393A8G40AB2-CWE?
Same 64GB / DDR4-3200 / 2Rx4 class, but BB4 and AB2 are different die revisions. Quote the exact number on your label.

Will any DDR4 server take 64GB 2Rx4 modules?
Most DDR4 RDIMM platforms do, but always confirm the QVL or memory guide for your CPU and motherboard.

Can I order only a few pieces?
Yes. Orders can start at two modules.

Do you quote OEM-labeled versions too?
Yes. Include the HPE, Dell, Cisco, Supermicro or Lenovo number if the server needs that label.