RDIMM vs LRDIMM: choosing the right server memory

Two module types dominate server memory. Here is how they differ and which one fits your workload and budget.

When you upgrade or specify a server, the memory decision usually comes down to two module types: RDIMM and LRDIMM. Both are registered, ECC-protected memory, but they solve slightly different problems.

RDIMM: the default choice

Registered DIMMs buffer the command and address signals. They are the most widely available server memory, cost less per gigabyte and have slightly lower latency. For most virtualisation hosts, databases and general-purpose servers, RDIMM is the right answer.

LRDIMM: when capacity matters most

Load-Reduced DIMMs also buffer the data lines, which lowers the electrical load on the memory channel. That lets a platform run more high-capacity modules per channel at full speed. Choose LRDIMM when you need the maximum memory per socket — large in-memory databases, analytics and dense virtualisation.

Practical rules

Never mix RDIMM and LRDIMM in the same server.
Match speed and rank across channels for best performance.
Check the platform's qualified memory list before ordering.

Not sure which modules your platform supports? Send us the server model and target capacity and we will check compatibility before we quote.

Have a specific requirement?

Get a Quote