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Green circuit board with black memory chips, gold edge connector, no heat spreader

OWC

OWC 16GB DDR4 2666MHz ECC Registered RDIMM memory upgrade for Lenovo ThinkAgile HX5520-C HX5521-C

SKU CH-S1CY-18CGY

16 GB DDR4 2666 MHz ECC registered RDIMM for Lenovo ThinkAgile HX5520-C and HX5521-C servers

  • Capacity16GB
  • Type288-Pin DDR4 ECC RDIMM
  • SpeedDDR4 2666 (PC4 21300)
  • CAS LatencyCL19
  • Voltage1.2V
  • ECCYes
  • ECC registered design protects data integrity in server workloads
  • 16GB capacity expands memory for demanding virtualisation tasks
  • DDR4 2666MHz CL19 speed matches Lenovo ThinkAgile HX5520-C and HX5521-C specs
  • 2V low-voltage operation reduces power draw in dense deployments
  • Replaces Lenovo part numbers 01AG618, 4X70P98202 and 7X77A01303 for direct compatibility

System-Specific ECC RDIMM for Lenovo ThinkAgile

This OWC 16GB DDR4 2666MHz ECC Registered RDIMM is built for Lenovo ThinkAgile HX5520-C and HX5521-C servers. It delivers 16GB capacity at PC4-21300 speed with CL19 latency and 1.2V operation. The module uses 288-pin 2Rx8 registered ECC technology suited for server and workstation workloads.

Replaces Lenovo part numbers 01AG618.

The upgrade replaces those factory modules and is backward compatible with 2133MHz and 2400MHz slots. It is designed for registered ECC platforms only and will not work in standard desktop computers. Mixing with unbuffered memory is not supported, so the jump is worth it when the system requires registered ECC DIMMs.

Simple DIMM installation

Installation follows standard 288-pin DIMM seating in the ThinkAgile memory slots. The main risk is attempting to use this registered ECC module in a consumer board or mixing it with unbuffered DIMMs, which prevents boot. No heat spreader is present, so airflow in the server chassis handles cooling.

Highlights

  • ECC registered design protects data integrity in server workloads
  • 16GB capacity expands memory for demanding virtualisation tasks
  • DDR4 2666MHz CL19 speed matches Lenovo ThinkAgile HX5520-C and HX5521-C specs
  • 2V low-voltage operation reduces power draw in dense deployments
  • Replaces Lenovo part numbers 01AG618, 4X70P98202 and 7X77A01303 for direct compatibility

Specifications

BrandOWC
Part Number2R6D42R816GB
Capacity16GB
Type288-Pin DDR4 ECC RDIMM
SpeedDDR4 2666 (PC4 21300)
CAS LatencyCL19
Voltage1.2V
ECCYes
Buffered/RegisteredRegistered
Rank2Rx8
Heat SpreaderNo
Compatible SystemLenovo ThinkAgile HX5520-C
Lenovo ThinkAgile HX5521-C

Questions about this item

What slot type does the 288-pin RDIMM require on the ThinkAgile HX5520-C?

It fits a standard DDR4 288-pin DIMM slot on the server motherboard; no adapter is needed.

Which step do installers most often skip when adding this ECC registered module?

They forget to verify that all populated slots use registered ECC DIMMs — mixing with unbuffered memory prevents boot.

When should the 16 GB 2Rx8 module be replaced in a ThinkAgile HX5521-C?

Replace it if memory diagnostics report correctable ECC errors that exceed the platform threshold or if a DIMM fails POST.

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