4 Things to Know About Registered ECC Memory for Xeon E5 v3

Registered DDR4 ECC (RDIMM) is what your Xeon E5 v3 board expects Unbuffered DDR4 ECC (UDIMM) is rare for this platform and often won’t work or will run at reduced performance.

Most LGA 2011-3 boards are designed for RDIMMs Supermicro, ASRock, and Gigabyte workstation boards from that era require registered memory because the E5 v3 memory controller is built for its extra buffering, especially with multiple ranks and higher capacities.

UDIMMs might work on some consumer boards, but it’s not guaranteed On ASUS X99 series boards, unbuffered sticks may work in a pinch if you stick to 2 slots, but don’t count on it.

Check your motherboard’s QVL, but registered ECC is the safe bet Buy PC4-2133 or 2400 registered ECC sticks off eBay—they’re cheap and plentiful. Don’t overthink it.