I have Dell PowerEdge R210 II server with 4Gb of memory installed. And I also have 8Gb memory module. I replaced 4Gb with 8Gb – server is working ok. But mixing memory in different ways got error "Unsupported memory configuration. DIMM mismatch across slots detected".
How can I install them both to get 12Gb of memory?
P.S. From server documentation: "Memory modules of different sizes can be mixed in sockets 1 to 4 (for example, 2 GB and 4 GB), but all populated channels must have identical configurations."