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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

  • Total capacity16 GB
  • Rated speedDDR4 2666 (PC4 21300)
  • CAS latencyCL19
  • Rated voltage1.2 V
  • Buffer typeRegistered
  • Memory rank2Rx8
  • 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.

How it compares

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

Price $108.99
Cheaper than about 67% of the 21,161 comparable items (median $397.99).
Total capacity 16 GB
Lower than about 70% of the 20,941 comparable items (median 32 GB).
Price per GB $6.81 per GB
Cheaper than about 58% 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 number2R6D42R816 GB
Total capacity16 GB
Product type288-Pin DDR4 ECC RDIMM
Performance
Rated speedDDR4 2666 (PC4 21300)
Memory
CAS latencyCL19
ECC supportYes
Buffer typeRegistered
Memory rank2Rx8
Heat spreaderNo
Power
Rated voltage1.2 V
Compatibility
Compatible systemsLenovo 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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