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
Single green 288-pin DDR4 RDIMM module, bare chips, no heat spreader

OWC

OWC 128GB DDR4 2666 ECC Registered RDIMM 2R6D48R4128G

SKU CH-X33W-0493R

A 128GB DDR4 2666 ECC registered RDIMM with CL19 latency and 1.2V operation, built for the ASUS KNPA-U16 server motherboard

  • Total capacity128 GB
  • Rated speedDDR4 2666 (PC4 21300)
  • CAS latency19
  • Rated voltage1.2 V
  • Buffer typeRegistered
  • Memory rank8Rx4
  • 128 GB single-module capacity for high-density server memory
  • ECC registered design detects and corrects data errors in critical workloads
  • 2666 MHz DDR4 speed with CL19 latency for responsive performance
  • 2 V operation reduces power draw in dense configurations
  • Backward compatible with 2133 MHz and 2400 MHz systems

Server-grade ECC RDIMM

This OWC module delivers 128GB of DDR4 2666 registered ECC memory in a single 288-pin DIMM. It is built for ASUS KNPA-U16 server motherboards and similar workstation or NAS platforms that require registered modules with error correction. The 8Rx4 organisation and CL19 timing meet JEDEC PC4-21300 specifications at 1.2V.

Registered slot requirement

The module fits a standard DDR4 RDIMM slot and must not be mixed with unbuffered or load-reduced DIMMs. Systems that accept registered ECC memory can use this upgrade to populate a single channel, leaving remaining slots free for additional capacity. Backward compatibility with 2133MHz and 2400MHz buses allows deployment in older DDR4 platforms without configuration changes.

128GB single-module density

One stick provides 128GB, enabling high total memory when multiple slots are available. The registered buffer and ECC circuitry maintain data integrity under sustained server workloads such as virtualisation, databases or large-file processing. Workloads that exceed the module count supported by the motherboard will require a platform with more memory channels.

How it compares

Measured against everything we stock in Model-Specific Memory Upgrades, at today’s prices. Recalculated every night.

Price $664.99
Pricier than about 55% of the 21,161 comparable items (median $397.99).
Total capacity 128 GB
Higher than about 70% of the 20,941 comparable items (median 32 GB).
CAS latency 19
Lower than about 70% of the 483 comparable items (median 22).
Price per GB $5.20 per GB
Cheaper than about 74% of the 20,941 comparable items (median $8.19 per GB).

New to this? Buying memory and SSDs with crypto — what to check, what it costs to pay, and what is never asked for.

Specifications

Product
Brand nameOWC
Part number2R6D48R4128G
Total capacity128 GB
Product type288-Pin DDR4 ECC RDIMM
Performance
Rated speedDDR4 2666 (PC4 21300)
Memory
CAS latency19
ECC supportYes
Buffer typeRegistered
Memory rank8Rx4
Heat spreaderNo
Power
Rated voltage1.2 V
Compatibility
Compatible systemsASUS Server Motherboard KNPA-U16

Questions about this item

Will the 128GB DDR4 2666 module downclock automatically if my ASUS KNPA-U16 only supports 2133MHz or 2400MHz?

Yes, the module is backward compatible with 2133MHz and 2400MHz speeds and will run at the highest speed the motherboard allows.

How much power does the 1.2V ECC Registered RDIMM draw under continuous server workloads?

The module operates at the standard DDR4 voltage of 1.2V; total power draw scales with capacity and rank count but stays within JEDEC limits for registered DIMMs.

Does my ASUS KNPA-U16 motherboard need to support 8Rx4 registered ECC DIMMs for this 128GB module to work?

Yes, the board must accept 288-pin DDR4 ECC Registered memory with an 8Rx4 rank configuration; the KNPA-U16 is listed as a compatible system.

More in Model-Specific Memory Upgrades

Similar items