This message was posted on behalf of Intel Corporation
In order to get a server working with a dual CPU configuration, it is required to use the exact same model of processor with the same stepping.
If you would like to get more information about how a dual socket system can be configured, please visit the Servers forums or contact other support services for servers here: http://www.intel.com/content/www/us/en/support/contact-support.html?iid=intelfb
Servers Forums: https://communities.intel.com/community/tech/servers
Hope this clarifies your inquiry and have a nice week!