Is all memory module you have are same model and supported in PowerEdge R510? You can check "System Memory" section on page 114 of below link for supported memory and configurations for PowerEdge R510. [URL] 
Hello, I have server power edg r510 in my university work, I want to install ram 128gb on it, but I do not how to configure it, I have 8 x 16gb, how do it ? when put all ram "8 * 16" the server is not accept and show me only 16gb ... any one tell me how to do it ?!! plz...
dell power edg r510 - ram configure help