5 Things to Know About Registered ECC (RDIMM) for Dual-Socket Servers

Unbuffered ECC only works in single-CPU setups The Xeon E5-2670 can technically use unbuffered ECC, but only with one processor. Adding a second CPU requires registered DIMMs.

Dual-socket boards won’t boot with unbuffered RAM Most dual-socket LGA2011 boards refuse to start with UDIMMs installed. It’s not a preference—it’s a hard requirement.

Registered modules reduce electrical load Unbuffered sticks put too much strain on the memory bus with two CPUs. RDIMMs use a buffer chip to offload that, ensuring reliable communication between both processors.

Cheap RDIMMs are easy to find 16GB and 32GB registered sticks are plentiful and inexpensive because old server RAM has low demand. Hunt those down for your dual E5-2670 build.

Check your motherboard manual It will explicitly state “RDIMM only” for dual-CPU configurations. Don’t overthink it—unbuffered is for single-CPU workstations, registered is for dual-socket.