DDR3 DDR4 LRDIMM — Load-Reduced ECC Server Memory 8GB-256GB

ECC-LRDIMM | ECC LOAD REDUCED SERVER MEMORY | CATALOG

NEMIX RAM DDR3, DDR4 LRDIMM are high-capacity, server-class memory solutions engineered for maximum performance and density in demanding data center environments. Backed by a Lifetime Replacement Warranty, these DDR4 LRDIMM represent a significant advancement in memory technology, specifically designed to optimize storage capabilities and data center efficiency for virtualization, cloud computing, and high-performance computing.

Why Upgrade with NEMIX RAM LRDIMM?

Performance and Capacity Leadership:

Exceptional Density and Speed: NEMIX RAM DDR3, DDR4 LRDIMM offer high speeds, typically ranging from DDR3 1333MHz to DDR4 3200MHz, ensuring robust performance for data-intensive workloads. Their key advantage lies in their significantly higher density options, commonly available in 8GB thru 256GB Modules, This allows for greater memory footprint per server, crucial for virtualized environments and large datasets.
Enhanced Capacity per Server: LRDIMM are designed to maximize the amount of RAM that can be installed in a server, overcoming the limitations of standard RDIMMs in high-density configurations. This increased capacity directly translates to the ability to run more virtual machines, handle larger in-memory databases, and improve overall application responsiveness.
Optimized for Data Centers: LRDIMM technology is specifically tailored for the rigorous demands of modern data centers, where maximizing server utilization and memory capacity within space and power constraints is paramount.

Key Advantages:

Power Efficiency: Operating at a low voltage of 1.2V, DDR4 LRDIMM contribute to energy savings and reduced heat generation compared to previous generations. While the power consumption per module might be slightly higher than lower-density RDIMMs due to the increased components, the overall efficiency gains from higher server utilization can be substantial.
Increased Bandwidth: Like other modules, LRDIMM offer higher bandwidth per core, facilitating faster data processing and improved performance for demanding applications.
Error-Correcting Code (ECC) Support: NEMIX RAM DDR3, DDR4 LRDIMM incorporate ECC technology, providing critical data integrity by detecting and correcting internal data errors. This is essential for maintaining the reliability of large memory configurations in mission-critical data center environments.

Load-Reduced Architecture: The "Load-Reduced" aspect of LRDIMM is crucial. They feature an isolation buffer that reduces the electrical load on the memory controller. This allows more DIMMs to be installed per channel without negatively impacting signal integrity and performance, enabling the high-density configurations LRDIMMs are known for.

What "load-reduced" actually does

A memory controller drives every DRAM chip on every module in a channel. On a registered DIMM (RDIMM) the register buffers only the command and address lines; the data lines still run straight from the controller to every rank of DRAM, so each rank adds electrical load. That load is what limits how many ranks a channel can carry and how fast it can run them — which is why a fully populated RDIMM channel drops speed, and why quad-rank RDIMMs were never practical past one per channel.

An LRDIMM adds a memory buffer that sits on the data lines too. The controller sees one buffer per module regardless of how many ranks are behind it. Four physical ranks — or eight, in a 3DS stacked module — present to the controller as one or two, the channel's electrical load stays low, and the full rated speed holds at two or three DIMMs per channel where RDIMMs would have to slow down. That is the whole point: more capacity per channel at full speed.

The cost is a buffer on the data path, which adds a small amount of latency (on the order of one clock) and a few watts per module for the buffer itself. On a lightly loaded channel a same-capacity RDIMM is marginally faster; on a fully loaded channel the LRDIMM wins on both capacity and speed.

RDIMM or LRDIMM — where the line falls

Situation	Buy	Why
One DIMM per channel, any capacity the platform lists as RDIMM	RDIMM	No load problem to solve; RDIMM is cheaper and slightly lower latency.
Two DIMMs per channel with 32GB or 64GB modules on DDR4	RDIMM, usually	Dual-rank RDIMMs hold rated speed at 2DPC on most Xeon Scalable and EPYC platforms. Check the vendor's memory speed table for your CPU.
128GB or 256GB per module on DDR4	LRDIMM	These capacities exist only as LRDIMM (128GB) or 3DS LRDIMM (256GB). There is no RDIMM alternative on DDR4.
Maximum capacity a DDR4 platform supports — 1.5TB, 3TB, 4TB per socket	LRDIMM	Reaching the platform ceiling requires the largest module in every slot; that module is an LRDIMM.
Two or three DIMMs per channel on Xeon E5 v3 / v4 or Xeon Scalable 1st Gen at full speed	LRDIMM	These platforms cut RDIMM speed at 2DPC and again at 3DPC; LRDIMM holds the rated speed.
DDR3 platforms needing 32GB or 64GB modules	LRDIMM	DDR3 32GB is quad-rank RDIMM (slow, one per channel) or LRDIMM (full speed, 2–3 per channel); 64GB is LRDIMM only.
DDR5 platforms	RDIMM	DDR5 RDIMMs reach 128GB and 256GB on their own; DDR5 LRDIMM is rare and most platforms do not list it. Its role is taken by DDR5 MRDIMM on the newest platforms.

Platform support

Generation	Platforms	LRDIMM speeds	Capacities
DDR3 LRDIMM (240-pin, 1.35V / 1.5V)	Intel Xeon E5-2600 v1 / v2 (Sandy Bridge-EP, Ivy Bridge-EP), E7 v2; Dell 12G, HPE Gen8, Supermicro X9 / X10 (DDR3 boards), Cisco UCS M3, Lenovo x3650 M4	1333, 1600, 1866	16GB, 32GB, 64GB
DDR4 LRDIMM (288-pin, 1.2V)	Intel Xeon E5-2600 v3 / v4, E7 v3 / v4, Xeon Scalable 1st Gen (Skylake-SP), 2nd Gen (Cascade Lake), 3rd Gen (Ice Lake / Cooper Lake); AMD EPYC 7001, 7002, 7003; Dell 13G / 14G / 15G, HPE Gen9 / Gen10 / Gen10 Plus, Supermicro X10 / X11 / X12 / H11 / H12, Cisco UCS M4 / M5 / M6, Lenovo ThinkSystem SR6xx / SR8xx and x3650 M5	2133, 2400, 2666, 2933, 3200	32GB, 64GB, 128GB, 256GB (3DS)

Two exceptions worth knowing. Single-socket entry servers — Xeon E-2100 / E-2200 / E-2300, Ryzen, Xeon D — take UDIMM or RDIMM only and do not accept LRDIMM at all. And within the platforms above, the CPU sets the speed: a 3200 LRDIMM in a Cascade Lake server runs at 2933 or 2666 by SKU, and in a Broadwell server at 2400. The vendor's memory table for the specific processor is the authority; our listings state the speed the module runs at in the systems it is listed for.

Capacity in practice: what a socket will hold

Platform	Slots per socket	Max with RDIMM	Max with LRDIMM
Xeon E5-2600 v3 / v4	12 (4 ch × 3)	768GB (12×64GB)	1.5TB (12×128GB)
Xeon Scalable 1st / 2nd Gen	12 (6 ch × 2)	768GB (12×64GB)	1.5TB (12×128GB); 3TB with 256GB 3DS on "L" / "M" SKUs
Xeon Scalable 3rd Gen (Ice Lake)	16 (8 ch × 2)	2TB (16×128GB RDIMM)	4TB (16×256GB 3DS)
EPYC 7002 / 7003	16 (8 ch × 2)	2TB	4TB (16×256GB 3DS)

Xeon Scalable 1st and 2nd Gen ship with a per-socket memory limit tied to the SKU suffix — a standard SKU is capped at 1TB, "M" at 2TB, "L" at 4.5TB with Optane. Buying 256GB LRDIMMs for a standard-SKU Gold 6248 gets you 1TB and no more; the processor, not the slot count, is the ceiling. Check the SKU before sizing above 1TB.

Ranks, 3DS, and reading the part

The rank code on the label — 2Rx4, 4Rx4, 8Rx4 — is the physical organization. A 64GB DDR4 LRDIMM is 4Rx4: four ranks of x4 DRAM behind the buffer, presented as two. A 128GB LRDIMM is typically 4Rx4 built on 16Gb DRAM, or 8Rx4 on 8Gb. A 256GB module is 8Rx4 3DS: DRAM dies stacked and through-silicon-bonded, two or four dies per package, so eight logical ranks fit in one module's footprint; the buffer presents them as two. 3DS LRDIMM requires platform support — Xeon Scalable 2nd Gen onward and EPYC 7002 onward list it; E5 v4 does not.

The DRAM makers mark load-reduced in the part number: Samsung M386 (versus M393 for RDIMM), Micron MTA…LS (versus …PZ), SK hynix HMAA…L or HMABAGL. OEM parts carry it in the description — Dell's SNP…/128G at 128GB is LRDIMM, HPE's option descriptions say "Load Reduced", Supermicro's are MEM-DR…-LR…. Every NEMIX RAM LRDIMM listing states the rank and 3DS where it applies.

Population rules

Never mix LRDIMM with RDIMM in one system. Not in a channel, not across channels, not across sockets. The controller trains the channel for one buffer type; a mixed set will not post on most platforms and will run degraded on the rest. If you are moving to LRDIMM, the RDIMMs come out.
Match capacity and rank across a channel. Mixed capacities are allowed on most platforms but cost interleave efficiency; identical modules in every populated slot is the documented optimal configuration.
Fill every channel before doubling any. Six or eight channels per socket, one module each, before adding the second DIMM per channel. An unbalanced population across channels or sockets is the most common cause of a server benchmarking slower after an upgrade.
Follow the vendor's slot order. Dell, HPE, Lenovo, and Cisco each print it on the chassis lid and in the manual; the order is by channel, not by slot number.
3DS needs a platform that lists it. A 256GB 3DS LRDIMM in a system that only lists 128GB will not be recognized at full capacity, or at all.

Where LRDIMM earns its cost

Any workload where the working set has to sit in memory and the platform's RDIMM ceiling is not enough: in-memory databases (SAP HANA sizing is memory-first by design), large virtualization hosts where VM density is bounded by RAM before CPU, VDI, analytics against datasets that fit in a few terabytes, and consolidation projects that replace several older hosts with one fully populated one. Where the platform's RDIMM maximum already covers the workload, RDIMM is the better buy; LRDIMM is for the systems that need to go past it.

How to check what is installed

The management controller — iDRAC, iLO, XCC, CIMC, or IPMI → Memory — shows type (RDIMM / LRDIMM), capacity, rank, and speed per slot without powering down.
Linux: sudo dmidecode -t memory shows "Type Detail: Registered (Buffered)" for RDIMM and "Load Reduced" for LRDIMM, with part number per slot.
The module label states LRDIMM or LR, the rank code, and the part number.

Why NEMIX RAM LRDIMM

Every NEMIX RAM LRDIMM is Specc'd on Micron, Samsung, or SK hynix DRAM with the buffer and register set specified for the platform generation, to the specification of the OEM module it replaces — capacity, rank, speed, 3DS where the part is 3DS — 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

LRDIMM upgrades are usually whole-system replacements — every slot, both sockets, matched. 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 correct module and count per system, with the SKU memory ceiling checked. Volume and reseller pricing is available on request.

Frequently asked

Can I add LRDIMMs to a server that already has RDIMMs? No. Replace the full set. This is the single most common LRDIMM ordering error.

Is LRDIMM faster than RDIMM? At one DIMM per channel, no — an RDIMM is marginally lower latency. At two or three DIMMs per channel on platforms that throttle RDIMM, yes — LRDIMM holds the rated speed. Capacity is the reason to buy it; speed is a side benefit in loaded channels.

Does LRDIMM use more power? A few watts per module for the buffer. Per gigabyte it is usually lower than the RDIMMs it replaces, because one 128GB module replaces two 64GB ones.

My server lists 3TB max but I can only reach 1TB. Check the processor SKU. Xeon Scalable 1st / 2nd Gen standard SKUs cap at 1TB per socket; "M" and "L" SKUs go higher. The chassis maximum assumes the top SKU.

Do I need LRDIMM on a DDR5 server? Almost never. DDR5 RDIMMs reach 128GB and 256GB and hold speed at 2DPC on most platforms; DDR5 LRDIMM is rare and the newest platforms use MRDIMM for the same role.

Does upgrading void the server warranty? No. Every server vendor 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

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NEMIX RAM DDR3, DDR4 LRDIMM are available in high-density options and various speeds, including 8GB, 256GB, and beyond, depending on the latest technology. As DDR4 technology continues to evolve, NEMIX RAM remains committed to providing cutting-edge, high-capacity memory solutions designed to meet the intensive demands of today's data centers and high-performance computing environments.

ECC-LRDIMM | ECC LOAD REDUCED SERVER MEMORY | CATALOG