Blake.fletcher, The slots B1-B4 are currently unusable since you don't have a second CPU installed. Generally, the R510 has quite unique memory configuration. Refer to the illustration below: [IMAGE] It has 2 banks consisting of slots A1, A2 & A3 and the other bank is just slot A4. Memory in each of the banks has to be the same and can't be mixed. For 2 CPUs, the memory has to match between the banks as well. However, for optimal performance; it is recommended that same size of memory be populated across the channels or banks. Based on your current configuration, you will have: A1 & A2 - 8 GB, a total of 16 GB RAM. You might consider purchasing  2 more 8 GB DIMMs to populate in A4 & A3 slots. A similar configuration shall apply to the second CPU if installed.This offers optimal memory configuration for you. Let me know whether you have any further questions
Hi, we have a PowerEdge R510 and would like to add more RAM. Currently, there are x3 4GB sticks in slots A1-A3. We bought x2 8GB sticks and are attempting to install them in any of the B1-B4 slots, but they aren't being recognized. This server doesn't have a second CPU installed next to the B1-B4 memory bank, is that an issue? The memory mode is set to optimizer. What am I missing and why isn't the RAM recognized? 
Memory question