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Green 288-pin DDR4 ECC RDIMM module with black chips, no heat spreader

OWC

OWC 2R6D44R464GB 64GB DDR4 2666 CL19 4Rx4 ECC RDIMM server RAM

SKU CH-HD4F-N5PRY

64 GB DDR4 2666 ECC registered DIMM for servers, workstations and NAS, CL19 1.2 V 4Rx4 with 2133/2400 MHz backward compatibility

  • Total capacity64 GB
  • Rated speedDDR4 2666 (PC4 21300)
  • CAS latencyCL19
  • Rated voltage1.2 V
  • Buffer typeRegistered
  • Memory rank4Rx4
  • 64 GB capacity scales server workloads
  • ECC registered design protects data integrity
  • DDR4 2666 CL19 speed matches OEM spec
  • 2 V operation lowers power draw
  • JEDEC and RoHS compliant for warranty-safe upgrades

Server ECC RDIMM for Workstations

This 64GB DDR4 registered DIMM targets servers, workstations and NAS systems that require ECC error correction. It is not compatible with standard desktop motherboards or unbuffered memory configurations. The module follows JEDEC and RoHS standards for warranty-safe deployment.

64GB capacity at DDR4 2666 CL19

The single module delivers 64GB via a 4Rx4 organisation running at 1.2V. It operates at PC4-21300 2666MHz with CL19 latency and remains backward compatible with 2133MHz and 2400MHz bus speeds. Systems needing higher density per slot or lower latency than CL19 will not be served by this part.

Replaces Fujitsu S26361-F4026 variants

This OWC module directly replaces Fujitsu part numbers ending in L764, L364, E764 and E364. The upgrade is worthwhile when extending the life of existing infrastructure or building new servers that specify these exact OEM part numbers. Mixing with load-reduced or unbuffered DIMMs is not supported.

How it compares

Measured against everything we stock in ECC Server RAM, at today’s prices. Recalculated every night.

Price $385.99
Pricier than about 65% of the 6,523 comparable items (median $188.99).
Total capacity 64 GB
Higher than about 70% of the 6,064 comparable items (median 32 GB).
Price per GB $6.03 per GB
Cheaper than about 63% of the 6,064 comparable items (median $7.25 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 number2R6D44R464 GB
Total capacity64 GB
Product type288-Pin DDR4 ECC RDIMM
Performance
Rated speedDDR4 2666 (PC4 21300)
Memory
CAS latencyCL19
ECC supportYes
Buffer typeRegistered
Memory rank4Rx4
Heat spreaderNo
Power
Rated voltage1.2 V

Questions about this item

Will this 64GB DDR4 2666 CL19 4Rx4 ECC RDIMM run alongside my existing 2133MHz or 2400MHz registered ECC modules?

Yes — the module is backward compatible with 2133MHz and 2400MHz DDR4 registered ECC DIMMs; all sticks will operate at the speed of the slowest installed module.

How can I verify the 64GB DDR4 2666 CL19 4Rx4 ECC RDIMM is detected and running with error correction after installation?

Check the server BIOS or UEFI memory information screen: it should show 64GB per module, 2666MHz (or the down-clocked speed), registered ECC mode active, and zero correctable errors in the system event log.

Does the 288-pin 1.2V ECC RDIMM ship alone, or are any brackets, cables or additional parts included?

Only the memory module is supplied; no brackets, cables or extra hardware are included.

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