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Green bare circuit board DDR5 RDIMM module with black memory chips and gold edge connector

OWC

OWC 128GB DDR5 4800 CL40 4Rx4 288-pin 1.1V ECC RDIMM memory upgrade

SKU CH-TK8A-MJC2H

Single 128 GB DDR5 ECC registered DIMM at 4800 MT/s CL40 for Lenovo ThinkSystem SR635 V3, SR645 V3, SR650 V3, SR655 V3 and SR665 V3 servers

  • Total capacity128 GB
  • Rated speedDDR5 4800 (PC5 38400)
  • CAS latencyCL40
  • Rated voltage1.1 V
  • Buffer typeRegistered
  • Memory rank4Rx4

Capacity 128GB

  • 128 GB capacity extends server memory headroom
  • DDR5 4800 CL40 delivers high-throughput data rates
  • ECC registered design protects data integrity in critical workloads
  • 1 V operation reduces power draw per module
  • Validated for ThinkSystem SR635 V3 SR645 V3 SR650 V3 SR655 V3 SR665 V3

Single-module 128 GB DDR5 ECC RDIMM

This OWC module provides 128 GB of DDR5 4800 CL40 registered ECC memory in a single 288-pin DIMM. It is built for Lenovo ThinkSystem SR635 V3, SR645 V3, SR650 V3, SR655 V3 and SR665 V3 servers and workstations that require registered ECC DDR5.

Verify registered ECC DDR5 slots and CPU support

Before ordering, confirm your system accepts 4Rx4 registered ECC DDR5 at 1.1 V and that the CPU memory controller supports this speed and rank configuration. This module will not work in platforms that only take unbuffered or load-reduced ECC memory, nor in standard desktop boards.

Replaces Lenovo part numbers 4X71M22551 4X77A77034

The module ships as a direct replacement for those Lenovo part numbers and carries OWC’s limited lifetime warranty with free technical support. No additional cables, brackets or software licences are included in the package.

How it compares

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

Price $3,796.99
Pricier than about 76% 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).
Price per GB $29.66 per GB
Pricier than about 84% of the 20,941 comparable items (median $8.19 per GB).

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Specifications

Product
Brand nameOWC
Part number4R8D54R4128G
Total capacity128 GB
Product type288-Pin DDR5 ECC RDIMM
Performance
Rated speedDDR5 4800 (PC5 38400)
Memory
CAS latencyCL40
ECC supportYes
Buffer typeRegistered
Memory rank4Rx4
Heat spreaderNo
Power
Rated voltage1.1 V
Compatibility
Compatible systemsLenovo ThinkSystem SR635 V3
Lenovo ThinkSystem SR645 V3
Lenovo ThinkSystem SR650 V3
Lenovo ThinkSystem SR655 V3
Lenovo ThinkSystem SR665 V3

Other versions of this model

5 more in the same range

Questions about this item

Does the 128GB DDR5 4800 CL40 4Rx4 module ship alone or with extra parts?

The module is a single 128GB DDR5 4800 PC5-38400 CL40 4Rx4 288-pin 1.1V ECC Registered DIMM; no additional components are included.

Which capacity and speed version should I select for a ThinkSystem SR650 V3?

This 128GB DDR5 4800 CL40 4Rx4 288-pin 1.1V ECC RDIMM is the specified upgrade for SR650 V3 and the other listed ThinkSystem models.

What does the 4800 CL40 rating mean for real-world server throughput?

The module runs at DDR5 4800 MT/s with CAS latency 40, delivering PC5-38400 bandwidth for registered ECC workloads on compatible ThinkSystem servers.

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