MK008,  That is correct, you should be able to simple swap them out. I would update the BIOS and ESM/Drac prior to doing so though. BIOS- [URL]  ESM-[URL] In regards to using the existing as well,  you can add them so long as the larger dimms are first, and all 3 channels match. So you can place new 16gb in A1, B1, A2, B2, A3, B3. Then place the 4gb in A4, B4, A5, B5, A6, and B6. That should work for you. Let me know if this helps.
I have a PowerEdge R710 with dual CPUs and I am upgrading the memory capacity. I have ordered 6x 16GB 2Rx4 RDIMM 1333MHz LV. Current Config: A1, A2, A3: 4GB, 1333, 2RX8, 8, 240, Regulatory, Low VoltageB1, B2, B3: 4GB, 1333, 2RX8, 8, 240, Regulatory, Low VoltageTotal: 24GB 2 Questions: AM I correct in saying I can simply remove the existing DIMMs and install the 16GB DIMMs into the same slots? eg:A1, A2, A3: 16GB B1, B2, B3: 16GB Total: 96GB. How can I use the existing 4GB DIMMs in addition to the 16GB DIMMs? What would the layout be?
RAM Upgrade Options