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Two green DDR5 RDIMM modules in anti-static tray

NEMIX RAM

NEMIX RAM 256GB (2x128GB) DDR5 6400 CL52 ECC RDIMM ASRock Rack GNRAPD12DNO memory upgrade

SKU CH-2J2X-2AKEW

256GB dual-rank DDR5-6400 ECC RDIMM kit validated for ASRock Rack GNRAPD12DNO servers

  • Capacity256GB (2 x 128GB)
  • Type288-Pin DDR5 RDIMM
  • SpeedDDR5 6400 (PC5 51200)
  • CAS LatencyCL52
  • Voltage1.10V
  • ECCYes

Size 256GB 2X128GB

Show 4 more configurations
  • 256 GB capacity from two 128 GB modules
  • DDR5 6400 speed with CL52 latency for rated performance
  • Registered ECC architecture prevents data corruption in servers
  • 1 V operation matches platform memory-controller requirements
  • Verified fit for ASRock Rack GNRAPD12DNO motherboard

256GB DDR5 6400 ECC RDIMM kit for ASRock Rack

This 256GB kit contains two 128GB DDR5 6400 RDIMMs built to the exact rank, voltage and timing the ASRock Rack GNRAPD12DNO motherboard expects. Registered ECC architecture lets every slot run fully populated at rated speed while correcting single-bit errors on the fly. It is intended for server administrators who need guaranteed compatibility and maximum capacity on this specific platform.

DDR5 6400 RDIMM limits

DDR5 6400 RDIMMs operate at 1.1V with a CAS latency of 52 and a 288-pin form factor that only fits DDR5 RDIMM slots. Registered buffering offloads the memory controller so all channels can be filled without signal degradation, but the modules will not work in UDIMM or SODIMM sockets. Buyers who need unbuffered memory or a different pin layout must choose another product.

2Rx4 rank and 1.1V specification

Each module uses a 2Rx4 organisation at 1.1V, the exact configuration the board's memory controller validates during training. If your system requires a different rank structure or voltage, this kit will not post or will run at reduced capacity. Always confirm the motherboard's qualified-vendor list before ordering.

Highlights

  • 256 GB capacity from two 128 GB modules
  • DDR5 6400 speed with CL52 latency for rated performance
  • Registered ECC architecture prevents data corruption in servers
  • 1 V operation matches platform memory-controller requirements
  • Verified fit for ASRock Rack GNRAPD12DNO motherboard

Specifications

BrandNEMIX RAM
SeriesNEMIX RAM Original Series Server Memory
ModelDDR5 ECC RDIMM Registered Server Memory
Part NumberMR51200-724K2
Capacity256GB (2 x 128GB)
Type288-Pin DDR5 RDIMM
SpeedDDR5 6400 (PC5 51200)
CAS LatencyCL52
Voltage1.10V
ECCYes
Buffered/RegisteredRegistered
Rank2Rx4
ChipsetMajor OEM Samsung, Micron, Hynix
Heat SpreaderNo
Compatible SystemASRock Rack
FeaturesDDR5 ECC RDIMM Motherboard Compatible
Package Content256GB 2X128GB DDR5 6400MHz PC5-51200 2Rx4 1.1V 288-PIN ECC RDIMM KIT

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Questions about this item

Should I choose the 256GB kit with two 128GB modules or a different capacity for my ASRock Rack GNRAPD12DNO?

This kit provides 256GB using two 128GB DDR5 RDIMMs. It is the exact-match upgrade specified for the ASRock Rack GNRAPD12DNO motherboard, matching the required rank, voltage, and timing so the memory controller recognises full capacity at rated speed.

What does the DDR5 6400 speed rating mean once the modules are installed in the server?

The modules run at DDR5 6400 (PC5 51200) with CL52 latency at 1.1V. Registered architecture offloads the memory controller, allowing every populated slot to operate at this rated speed and full capacity without downclocking.

Is the 288-pin RDIMM interface compatible with standard DDR5 UDIMM slots, and what does the registered design limit in practice?

No, 288-pin RDIMMs only fit registered DIMM slots. The registered (buffered) design caps electrical load on the memory controller, enabling stable operation when all slots are populated at 256GB total, while ECC corrects single-bit errors on the fly.

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