UCS C220 M5 - adding memory

[bendre18]

Currently the server has a total of 256GB, with 8x 32GB DIMMs, part number 36ASF4G72PZ-2G9E2

Based on the ordering guide spec sheet, these should have been LRDIMMs, but this part number seems to be an RDIMM. Trying to double the memory with the same type, just not sure if I should get:

4x UCS-MR-X64G2RW or 8x UCS-MRX32G2RW or 1x UCS-ML-256G8RW

Are they memory "kits" or actual modules? I thought I read the number before RW was the number of modules in a kit, but not sure if that's indeed the case.. TIA.

[Steven Tardy]

36ASF4G72PZ-2G9E2 is Cisco PID: UCS-MR-X32G2RT-H

This "MR" is an "RDIMM" which will not work with "ML" or "LRDIMM"[1].

RDIMMs cannot be mixed with LRDIMMs.

DIMM "kits" or pairs usually has a "x2" or "2x" in the PID.
The "RW" isn't a thing. But the "2R" or "8R" is number of "ranks".
The "W" (or "T") aligns with the JDEC "speed"[2].

[1] Cisco UCS C220/C240/ B200 M5 Memory Guide
[2] Wikipedia: JEDEC standard DDR4 module