Samsung M321RBJA0M22-CLP

Technical Overview

Samsung M321RBJA0M22-CLP is a 256GB DDR5-6400 RDIMM with a 4Rx4 organization and ECC. The module name is PC5-51200R. Samsung builds both the DRAM and the finished server module. This density uses 3DS (stacked) DRAM, so rank and platform support matter more than on a standard 64GB or 128GB stick.

Most requests start from the number on the label, or from a build that needs 256GB DDR5-6400 RDIMM 4Rx4. 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

• M321R — Samsung DDR5 RDIMM family
• BJA0 — 256GB module density
• M22 — die and package revision (3DS)
• CLP — DDR5-6400 speed grade

Use the full code on the quote. Nearby 128GB AJA0 codes are a different density and rank class.

Key Specifications

Part Number: M321RBJA0M22-CLP
Manufacturer: Samsung
Capacity: 256GB (1x 256GB)
Memory Type: DDR5 SDRAM
Module Type: RDIMM (Registered DIMM)
Speed: 6400 MT/s
Module Name: PC5-51200R
Rank / Organization: 4Rx4
Error Correction: ECC
Voltage: 1.1V
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 256GB 4Rx4 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, quote an LRDIMM equivalent, or send a photo of the current label.

Where This Module Is Used

• Replacing the same Samsung 256GB DDR5 RDIMM already in the server
• High-capacity upgrades that specify 256GB DDR5-6400 RDIMM, 4Rx4
• Dense memory 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:

• 256GB
• DDR5-6400 / PC5-51200R
• RDIMM
• 4Rx4
• ECC
• 1.1V / 288-pin

Do not treat a 128GB 2Rx4 module as a drop-in for this 256GB 4Rx4 part.

What to Send for a Quote

1. Part number: M321RBJA0M22-CLP
2. Quantity
3. Optional: server brand and model
4. Optional: photo of the module label
5. Or: 256GB + DDR5-6400 + RDIMM + 4Rx4

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

FAQ

Is this an LRDIMM?
No. It is a Samsung DDR5 RDIMM. Confirm the installed type before ordering.

Will any DDR5 server take 256GB modules?
Not always. Confirm the platform supports 256GB 4Rx4 RDIMM before you order.

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.