This message was posted on behalf of Intel Corporation
According to the information in our web site the memory the is fully supported by the Intel® E5-2640 v4 are DDR4 1600/1866/2133, as you can confirm on the following link:
Also on the following link you will be able to see further information about the memory that is supported by that processor:
If the memory that you are using complies with those specifications and still the PC does not work properly, in that case since you are using a server board with a dual socket configuration, the best thing to do will be to get in contact with the ASUS’s server department, so they can provide further technical assistance on this matter:
ASUS’s phone number: 1-877-339-2787
ASUS’s support site: https://www.asus.com/us/support/
Any questions, please let me know.