Nikolaj,   I started by pulling the factory installed module and instead installed the new Samsung module, however when booting, the BIOS says that no usable module is installed. I checked that it is correctly seated in the slot.   Not working Module: Samsung 8GB 1Rx4-2133P-RC0-10-DC0 (M393A1G40DB0-CPB0Q)   The T130 sever supports only unbuffered memory modules, UDIMM. The memory module in question is registered module, RDIMM which is not supported and as such the system renders it as unusable as it can not be detected. Consider using unbuffered memory module of P/N H5P71   As mentioned earlier, the issue here is that RDIMMs are not supported on the server and not mixing of memory modules of different ranks. Memory modules of different ranks can be mixed.
I just bought a Dell Poweredge T130 with 8GB RAM. I wanted to expand the memory to 16GB so I tried installing a 8GB ECC DDR4 Samsung module without success. I have zero experience using ECC RAM, so my guess is that there are requirements for the RAM that I'm unaware of.  I started by pulling the factory installed module and instead installed the new Samsung module, however when booting, the BIOS says that no usable module is installed. I checked that it is correctly seated in the slot.   Not working Module: Samsung 8GB 1Rx4-2133P-RC0-10-DC0 (M393A1G40DB0-CPB0Q) Factory installed module: SK Hynix 2Rx8 PC4-2133P-EE0-10 (HMA41GU7AFR8N-TF) I can see that the Hynix module that came installed in the PowerEdge is 2Rx8, and the Samsung is 1Rx4 - can this be the reason?  Best regards, Nikolaj 
Samsung DDR4 8G RAM stick not working in T130