Re: R710 Memory Upgrade possibility with mixing 4GB and 16GB modules
To max out the server with the dimms you specified you would need to install the 16gb dimms on A1, A2, and A3 as well as B1, B2, and B3. All the remaining dimms would be 4gb dimms. That will need to be set to Optimizer mode in the BIOS.
Basically the memory must match across all the channels.