Jackson14, That would NOT be a usable configuration, as I can tell by the population that you are using Advanced ECC Memory mode. Which doesn't support mixing dimms, the dimms must be identical.  What you will need to do to use these dimms is to boot to the BIOS (F2) and then change the Memory Mode to Optimizer. From there move the dimms to the following slots.  16gb dimms in A1, A2, B1, and B2. That is the 4 outside white tabbed slots, furthest from each processor.  Then the 8 4gb dimms would go in A4, A7, A5, and A8, as well as B2, B7, B5, and B8.  That configuration should allow you to achieve you dimm total and maximize performance.  Let me know how it goes.
Hello, can anybody tell me if this configuration will be valid in a R710 dual Processor? currently the Server has 32GB and I want to add 4x16GB to have 96GB (I have added those modules as example in A8, A9, B8, B9) This will be my desired configuration CPU1  CPU2  Thanks!  Marcelo
Mixing RAM Modules