ECC RDIMM — Registered Server Memory, DDR2 to DDR5

ECC-RDIMM | ECC REGISTERED SERVER MEMORY | CATALOG

NEMIX RAM ECC Registered RDIMM modules are stress tested for server-class and industrial-grade applications, backed by a Lifetime Replacement Warranty. Upgrading to NEMIX RAM SERVER MEMORY offers cutting-edge performance enhancements, focusing on reducing power consumption and significantly improving storage and data center efficiency. DDR5 represents the 5th generation of double data rate (DDR) SDRAM.

Why Upgrade with NEMIX RAM RDIMM?

NEMIX RAM RDIMM are specifically engineered for high-demand environments such as data centers, cloud computing, and professional-grade servers and workstations. Our DDR5 RDIMM offer substantial performance improvements over DDR4, providing:

Enhanced Performance: DDR5 RDIMM deliver twice the performance of DDR4, with speeds ranging from 4800 to 6400 MT/s (MHz). This substantial increase in bandwidth per core enhances data processing capabilities and system performance.
Improved Power Efficiency: Operating at 1.1V and featuring an on-DIMM 12V voltage regulator (PMIC), DDR5 RDIMM are designed for improved power efficiency. This helps to reduce energy consumption and heat output, contributing to a more stable and cooler system.
Advanced Stability: The buffer between the memory module and the system's memory controller enhances stability, especially in high-density memory configurations. DDR5 RDIMM always support ECC (Error-Correcting Code), ensuring data integrity by detecting and correcting errors.
Superior Bandwidth: DDR5 RDIMM provide more bandwidth per core compared to DDR4. For example, while DDR4-3200MHz memory offers up to 4.2 GB/s per core on an 8-core CPU, upgrading to DDR5-5600MHz memory with a 16-core CPU maintains 4.2 GB/s per core, eliminating the decline in bandwidth per core.
Faster Speeds: With DDR5’s minimum speed of 4800MHz being over 50% faster than the maximum DDR4 speeds of 3200MHz, DDR5 RDIMMs surpass DDR4’s bandwidth limitations, making them ideal for data-heavy and industrial applications.

What changed on the module, and why it matters when you buy

A DDR5 RDIMM is not a faster DDR4 RDIMM. Four things moved onto the module itself, and each one shows up in how the part is specified and populated.

Two independent 40-bit subchannels. A DDR4 RDIMM is one 72-bit channel (64 data + 8 ECC). A DDR5 RDIMM is two 40-bit halves (32 data + 8 ECC each), each with its own command path through the register. The controller schedules them separately, which is where much of the real-world bandwidth gain comes from — and why a DDR5 ECC RDIMM is 80 bits wide, not 72.
Power management on the module. The PMIC takes 12V from the slot and regulates 1.1V locally. The motherboard no longer does it, which is why a DDR5 slot delivers 12V and a DDR4 module cannot physically fit — the key notch is in a different place.
On-die ECC — which is not the ECC you are buying. Every DDR5 DRAM chip, including the ones on consumer modules, corrects single-bit errors inside the chip before data leaves it. That protects against cell-density effects; it does not protect the bus, the register, or the controller, and the system cannot see or log it. Side-band ECC — the extra 8 bits per subchannel on an RDIMM or ECC UDIMM, checked by the controller — is what servers require and what "ECC RDIMM" means. A non-ECC DDR5 UDIMM with on-die ECC is not server memory.
The register is now a full RCD with the SPD hub and sensors on the module. The management controller reads temperature per DIMM and the platform can throttle per module. Speed and timing come from the SPD; there is no XMP or EXPO on a server module.

Which speed your platform runs

Platform	Channels per socket	1 DIMM per channel	2 DIMMs per channel	Systems
Intel 4th Gen Xeon Scalable (Sapphire Rapids)	8	4800	4400	Dell 16G (R660, R760, R760xa), HPE Gen11 (DL360 / DL380), Lenovo V3 (SR630 / SR650), Cisco UCS M7, Supermicro X13
Intel 5th Gen Xeon Scalable (Emerald Rapids)	8	5600	4400	Same chassis with refreshed CPUs — Dell 16G, HPE Gen11, Lenovo V3, Cisco M7, Supermicro X13
Intel Xeon 6 (Granite Rapids / Sierra Forest)	8 or 12	6400 RDIMM · 8800 MRDIMM	5200	Dell 17G (R670, R770), HPE Gen12, Lenovo V4, Cisco M8, Supermicro X14
AMD EPYC 9004 (Genoa / Bergamo / Genoa-X)	12	4800	4800 or 4400 by vendor	Dell 16G (R6625 / R7625 / R7615), HPE Gen11 (DL325 / DL345 / DL385), Lenovo V3 (SR635 / SR645 / SR655 / SR665), Supermicro H13
AMD EPYC 8004 (Siena)	6	4800	—	Single-socket edge and telco chassis
AMD EPYC 9005 (Turin)	12	6000 (6400 on some boards)	4400 – 5200 by vendor	Dell 17G, HPE Gen12, Lenovo V4, Supermicro H14
Workstation: Xeon W-2400 / W-3400 / W-2500 / W-3500, Threadripper PRO 7000 WX / 9000 WX	4 or 8	4800 – 6400	4400 – 5200	Dell Precision 7875 / 7960, Lenovo ThinkStation P8 / PX, HP Z6 G5 / Z8 G5, Supermicro X13SWA / H13SSW

The rule that follows from the table: buy the speed the platform runs at one DIMM per channel, and expect the second DIMM per channel to lower it. A 6400 module in a Sapphire Rapids server runs at 4800; it fits and works, and you paid for speed the CPU cannot use. A 4800 module in an Emerald Rapids server runs at 4800 and leaves 5600 on the table. Our listings state the speed the module runs at in the systems it is listed for; the vendor's memory table for the specific processor SKU is the authority.

Capacities, ranks, and what the rank code tells you

Capacity	Organization	Notes
16GB	1Rx8	Entry; single-rank x8. Lowest bandwidth per channel; fine for one-per-channel minimum configurations.
32GB	1Rx4 or 2Rx8	The two organizations are not interchangeable in a mixed channel; match what is installed.
48GB	1Rx4 or 2Rx8 on 24Gb DRAM	The non-binary capacity. Supported on Sapphire Rapids and later, EPYC 9004 and later; check the vendor's list for the chassis.
64GB	2Rx4	The workhorse server module. Dual-rank x4 gives the best interleave on a single-DIMM channel.
96GB	2Rx4 on 24Gb DRAM	Non-binary; the cost-effective step between 64GB and 128GB on platforms that list it.
128GB	2Rx4 on 32Gb DRAM, or 4Rx4 (2H 3DS on 16Gb)	Two constructions in the market; the 2Rx4 version runs faster at 2DPC and is the one to prefer where the platform lists it.
256GB	8Rx4 (4H 3DS)	Stacked die; requires a platform that lists 3DS RDIMM. 1DPC only on most.

Dual-rank modules outperform single-rank of the same capacity in one-DIMM-per-channel configurations because the controller can interleave across ranks; the difference is a few percent in bandwidth-bound workloads. At two DIMMs per channel, total ranks per channel is what drives the speed reduction, and x4 versus x8 matters for the ECC scheme: most server platforms require x4 for full chipkill-class correction (Intel ADDDC / SDDC, AMD equivalent) and will run x8 with a reduced correction level. Where the vendor's list specifies x4, buy x4.

Population rules that hold on every DDR5 platform

Fill every channel first. Eight channels on Intel, twelve on EPYC. One module in each channel before a second in any; a socket with four of eight channels populated runs at half the memory bandwidth, which a database or an AI data-loading pipeline will show immediately.
Supported counts are not every number. Intel 8-channel supports 1, 2, 4, 6, and 8 modules per socket with 8 as the balanced configuration. AMD 12-channel supports 1, 2, 4, 6, 8, 10, and 12 with 12 balanced and 6 the balanced half-population; 8 and 10 leave channels unbalanced across the memory quadrants and are supported but slower. Buy in the count the vendor documents.
Identical modules per socket, identical sockets. Same capacity, rank, and organization in every populated slot; the second socket mirrors the first.
RDIMM only. These platforms do not accept UDIMM, ECC or not, and the slot key prevents it. DDR5 LRDIMM is rarely listed; MRDIMM is Xeon 6 only and does not mix with RDIMM.
Follow the vendor's slot order. It is printed on the chassis lid and in iDRAC, iLO, XCC, and CIMC; it runs by channel across the socket, not left to right.

Workstations take the same module

Xeon W-2400 / W-3400 and Threadripper PRO 7000 WX / 9000 WX are server memory controllers in a workstation socket: 4 or 8 channels of DDR5 RDIMM, and only RDIMM. A Precision 7875, ThinkStation PX, or Z8 G5 upgrade is the same 32GB / 64GB / 96GB 2Rx4 module a PowerEdge takes, with the same fill-every-channel rule — a 4-channel Xeon W-2400 board with two modules runs at half bandwidth just as a server would.

Reading the part number

The DRAM makers mark DDR5 RDIMM plainly: Samsung M321 (versus M323 for ECC UDIMM and M324 for non-ECC), Micron MTC…R in the RDIMM position (MTC40F2046S1RC48 is 64GB 2Rx4 4800), SK hynix HMCG…R (HMCG94MEBRA is 64GB 2Rx4). OEM parts: Dell AC-prefix codes and 370-AGxx / AHxx, HPE P43xxx-B21 and P64xxx-B21, Lenovo 4X77A, Supermicro MEM-DR5xx, Cisco UCS-MRX…. The manufacturer pages decode each vendor's code to the module.

How to check what is installed

The management controller — iDRAC 9, iLO 6, XCC 2, CIMC, or IPMI → Memory — shows capacity, rank, organization, speed, part number, and temperature per slot, and the current operating speed after training.
Linux: sudo dmidecode -t memory shows "Configured Memory Speed" alongside "Speed" — if the two differ, the platform trained the module below its rating, and the table above says why.
The module label carries capacity, speed, the rank code, and "ECC RDIMM" or "RDIMM".

Why NEMIX RAM DDR5 RDIMM

Every NEMIX RAM DDR5 RDIMM is Specc'd on Micron, Samsung, or SK hynix DRAM with the RCD, PMIC, and SPD hub specified for the platform generation, to the specification of the OEM module it replaces — capacity, rank, organization, speed, x4 where the vendor requires x4 — and run in the platform class it is listed for before it is offered. Some vendors' firmware shows an informational notice for memory not from their own catalog; it does not affect operation. Lifetime replacement warranty and free US-based technical support on every module.

Ordering for a fleet

A DDR5 server upgrade is usually a full population — every channel, both sockets, identical modules. NEMIX RAM is a registered federal supplier (UEI GV8MMYNDJ5J1, CAGE 59AB2) and accepts purchase orders with net terms for business, government, and education buyers. Send the models, processor SKUs, and target capacity per system to our sales team and we return one quote with the module, count, and trained speed per system. Volume and reseller pricing is available on request.

Frequently asked

Can I put DDR5-5600 in a Sapphire Rapids server? Yes; it runs at 4800. If the server may later receive Emerald Rapids CPUs, the 5600 module carries over at 5600 — otherwise buy 4800.

Will a DDR5 ECC UDIMM work in a PowerEdge R760? No. The slot is keyed for RDIMM and the controller is RDIMM-only. ECC UDIMM is for Xeon E-2400, Ryzen, and Ryzen PRO platforms.

Is 96GB a real capacity? Yes — 24Gb DRAM, JEDEC standard, listed by Dell, HPE, Lenovo, and Supermicro on Sapphire Rapids, Emerald Rapids, and EPYC 9004 and later. It is the better buy between 64GB and 128GB on those platforms.

Do I need 3DS for 128GB? Not anymore. 32Gb DRAM puts 128GB on a standard 2Rx4 module, which trains faster at 2DPC than the 4Rx4 3DS version. Prefer 2Rx4 where the vendor lists it.

The server shows the memory running slower than the module rating. Two DIMMs per channel, an unbalanced population, or a mixed set of ranks. Check the population against the vendor's table before assuming a fault.

Does upgrading void the server warranty? No. Every vendor on this page documents memory as customer-installable. Our lifetime warranty covers the module; the system warranty is unchanged.

NEMIX RAM can deliver any Configuration your Fleet Requires

Contact US

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NEMIX RAM ECC Registered RDIMM Modules available in a range of form factors and densities including.

DDR2,DDR3,DDR4,DDR5 - 2GB, 4GB, 8GB, 16GB, 24GB, 32GB, 48GB, 64GB, 96GB, 128GB, 256GB.

As technology evolves, NEMIX RAM will continue to offer memory modules to meet the growing demands of advanced computing environments.

ECC-RDIMM | ECC REGISTERED SERVER MEMORY | CATALOG