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Two green DDR5 ECC RDIMM modules, 288-pin, no heat spreaders

OWC

OWC 256GB (2x128GB) DDR5 4800 CL40 4Rx4 ECC RDIMM SR950 V3

SKU CH-JWZZ-VK94X

ECC registered DDR5 kit adds 256 GB across two 128 GB modules at 4800 MT/s CL40 for Lenovo ThinkSystem SR950 V3 servers

  • Capacity256GB (2 x 128GB)
  • Type288-Pin DDR5 ECC RDIMM
  • SpeedDDR5 4800 (PC5 38400)
  • CAS LatencyCL40
  • Voltage1.1V
  • ECCYes

Capacity 256GB (2 x 128GB)

  • 256GB total capacity with two 128GB modules
  • DDR5 4800 speed rated at PC5-38400
  • CL40 CAS latency at 1.1V operating voltage
  • ECC registered 4Rx4 design for server reliability
  • Validated for Lenovo ThinkSystem SR950 V3

Server ECC RDIMM kit

This OWC kit provides 256 GB of DDR5 registered ECC memory in two 128 GB modules. It runs at 4800 MT/s with CL40 latency at 1.1 V. The modules use a 288-pin 4Rx4 layout without heat spreaders. They are validated for the Lenovo ThinkSystem SR950 V3.

For SR950 V3 upgrades only

This memory suits administrators expanding a ThinkSystem SR950 V3 with registered ECC DDR5. It will not work in standard desktops, workstations that require unbuffered DIMMs, or systems that only accept load-reduced modules. Mixing with non-registered memory is not supported.

Registered 4Rx4 DDR5 at 4800 MT/s

The registered 4Rx4 organisation at 4800 MT/s is the specification that determines compatibility. The SR950 V3 memory controller must support registered ECC DDR5 with this rank geometry and speed. Verify the server's qualified vendor list before installing.

Highlights

  • 256GB total capacity with two 128GB modules
  • DDR5 4800 speed rated at PC5-38400
  • CL40 CAS latency at 1.1V operating voltage
  • ECC registered 4Rx4 design for server reliability
  • Validated for Lenovo ThinkSystem SR950 V3

Specifications

BrandOWC
Part Number4R8D54R4256P
Capacity256GB (2 x 128GB)
Type288-Pin DDR5 ECC RDIMM
SpeedDDR5 4800 (PC5 38400)
CAS LatencyCL40
Voltage1.1V
ECCYes
Buffered/RegisteredRegistered
Rank4Rx4
Heat SpreaderNo
Compatible SystemLenovo ThinkSystem SR950 V3

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Questions about this item

How do I install these 288-pin DDR5 RDIMMs in the ThinkSystem SR950 V3 without populating the wrong slots?

Power down the server, open the chassis, and insert each 128 GB module into the DIMM slots assigned to the target processor socket following the SR950 V3 memory population guide; the key notch on the 288-pin DDR5 connector prevents backward insertion.

What maintenance or replacement will this 256 GB ECC registered kit need over its service life?

No periodic maintenance is required; if a module fails the ECC registered design logs correctable errors and the server firmware will flag an uncorrectable fault so the single 128 GB DIMM can be swapped without replacing the pair.

What limit appears first when this 4Rx4 CL40 kit runs sustained workloads at 4800 MT/s?

The four-rank-per-module organisation increases electrical loading on the memory bus, so the memory controller typically hits its maximum supported rank-per-channel limit before thermal or bandwidth ceilings are reached.

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