Hacker News Reader

What is the difference between UDIMM and RDIMM and which one is preferred and why?

It seems RDIMM’s are mostly supported on higher end server boards but I haven’t seen a technical comparison of the two types.

View on HN

RDIMMs have buffers on the memory lines to improve signal integrity, this is only helpful when there are many slots on the same memory controller channel. (ex. Servers often support 4 DIMMs per channel)

I think RDIMMs are available in higher capacities than UDIMMs. But the registering adds additional latency. So if you need the capacity, RDIMM is the way to go. But if you don't, you might prefer UDIMMs.

Reply on news.ycombinator.com