Samsung 16GB ECC DDR4 2666MHz PC4-21300 1.2V 2Rx8 288-Pin ECC UDIMM Server RAM Memory Module M391A2K43BB1-CTD

The Samsung M391A2K43BB1-CTD is a 16GB DDR4-2666 ECC unbuffered UDIMM for compatible servers and workstations that require unregistered memory. It runs at 1.2V, uses a 2Rx8 rank layout, and has CL19 latency.

Recommended For

• Home-server or NAS builders who run workloads such as file serving, containers, or home-lab services and whose CPU and motherboard explicitly support ECC UDIMMs.
• Workstation users handling data-sensitive or long-running tasks who want ECC memory and have confirmed their system supports unbuffered ECC DIMMs.
• Owners of a compatible DDR4 ECC-UDIMM workstation or small server who need a 16GB replacement or expansion module matching that memory type and speed.
• Builders of compact or entry-level servers prioritizing ECC support and a simple unbuffered memory setup over the higher capacities enabled by registered DIMMs.

Real-World Use Scenarios

• In a compatible home NAS or file server, this module can add 16GB of memory with ECC support; if the CPU and motherboard enable ECC, it can help correct certain memory errors while the server handles files and backups.
• For a homelab running a hypervisor such as Proxmox, the module can expand memory available to virtual machines and services; whether ECC correction is active depends on platform support, not just installing the DIMM.
• When upgrading an entry-level server or workstation that requires ECC unbuffered DDR4, this stick can add capacity without switching to registered memory; check the system’s compatibility list before buying.
• For a small server used for several lightweight services—such as file sharing, home automation, or a game server—adding this module can provide more room for those services, but 16GB alone may not suit heavier virtual-machine or data workloads.
• For a system that already uses this exact module, it can serve as a replacement for a failed stick or as a matching-capacity addition; the system may run memory at a lower speed if its processor or motherboard specifies one.