We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Green rectangular circuit board with gold edge contacts and black memory chips on both sides

OWC

OWC 128GB DDR4 2666MHz CL19 4Rx4 ECC Registered RDIMM 1.2V 288-pin server RAM

SKU CH-VMXM-NRSXS

A single 128 GB DDR4 2666 MHz CL19 4Rx4 ECC registered RDIMM at 1.2 V for server, workstation or NAS upgrades

  • Capacity128GB
  • Type288-Pin DDR4 ECC RDIMM
  • SpeedDDR4 2666 (PC4 21300)
  • CAS LatencyCL19
  • Voltage1.2V
  • ECCYes

Capacity 128GB

Show 7 more configurations

Rank 4Rx4

  • 128GB single module maximises server capacity
  • ECC registered design protects data integrity in critical workloads
  • DDR4 2666MHz CL19 delivers reliable throughput for demanding tasks
  • 2V operation reduces power draw in dense configurations
  • Compatible with 2133MHz and 2400MHz systems for flexible deployment

Single 128GB DDR4 module

This OWC 128GB DDR4 2666MHz CL19 4Rx4 ECC Registered RDIMM is built for servers, workstations and NAS systems that require registered ECC memory. It operates at 1.2V and uses a 288-pin DDR4 form factor. The module will not work in standard desktop computers and cannot be mixed with unbuffered memory.

DDR4 2666 speed ceiling

The module runs at DDR4 2666 (PC4-21300) with CL19 latency and is backward compatible with 2133MHz and 2400MHz systems. It conforms to JEDEC specifications for registered DIMMs. Registered ECC memory is required by the platform; unbuffered or non-ECC modules are not supported in the same configuration.

128GB capacity in one slot

A single module provides 128GB of registered ECC capacity, allowing high-density memory configurations within limited DIMM slots. The 4Rx4 organisation suits platforms qualified for quad-rank registered DIMMs. Systems that do not support registered ECC or quad-rank modules cannot use this memory.

Highlights

  • 128GB single module maximises server capacity
  • ECC registered design protects data integrity in critical workloads
  • DDR4 2666MHz CL19 delivers reliable throughput for demanding tasks
  • 2V operation reduces power draw in dense configurations
  • Compatible with 2133MHz and 2400MHz systems for flexible deployment

Specifications

BrandOWC
Part Number2R6D44R4128G
Capacity128GB
Type288-Pin DDR4 ECC RDIMM
SpeedDDR4 2666 (PC4 21300)
CAS LatencyCL19
Voltage1.2V
ECCYes
Buffered/RegisteredRegistered
Rank4Rx4
Heat SpreaderNo

Other versions of this model

5 more in the same range

Same family, different memory, cooler or clock — compare before you commit.

Questions about this item

Should I pick the 128GB 2666MHz CL19 4Rx4 module or a smaller capacity?

Choose the 128GB module when your server or workstation needs maximum density per slot and the platform supports 4Rx4 registered ECC; smaller capacities use fewer ranks and may be required if the memory controller limits rank count per channel.

What does the 2666MHz rating deliver once the module is installed?

The module runs at 2666MHz CL19 when the platform supports that speed; if the system only supports 2133MHz or 2400MHz it will downclock automatically to the highest supported frequency while keeping ECC and registered operation.

How does the DDR4 288-pin registered ECC interface limit real-world use?

The 288-pin DDR4 registered ECC interface fits only server, workstation or NAS boards that accept 4Rx4 RDIMMs; it cannot be used in standard desktop motherboards or mixed with unbuffered memory, and voltage is fixed at 1.2V.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.