Hello   Yes, this is a validated memory module for the T620. We have it listed under several part numbers, 12C23 is one of the part numbers.   I was unable to locate this model number in our part database.   The first module does not appear to be validated, so I can't say for sure it will work. From your statement it sounds like it is working without issue for you. By just skimming the specifications I don't see a reason they cannot be used together. Your low voltage memory will operate at 1.5v when mixed with 1.5v memory, and they will negotiate down to the lowest common frequency. You should avoid mixing memory within a memory grouping(1-4, 5-8, 9-12). The memory you have is similar enough that you can probably mix it, but it should be avoided if possible. Thanks
Hello everyone,  I have Dell PE T620 configured with 5pc's x16gb Samsung Ram which has the following details : Samsung 16GB 2Rx4 PCL3-12800R 11-12-E2-D3 M393B2G70QH0/1426  When I asked the supplier to provide more ram compatible with my server,  he sent me the following Item: Samsung 16GB 2Rx4 PC3-14900R 13-12-E2-P3 M393B2G70DB0-CMA/1415   I could find that the 2nd part number is listed for dell PE T620 I just wanted to insure please , if I have the 1st part number already used in my server, will I be able to use the 2nd one as well? any reply or help is highly appreciated  
PE T620 Compatible ram list