I'm wondering if the X9DR3-LN4F+ supports the E5-2620 6-core processor. I can't find a processor compatibility matrix for this motherboard on your website, and a comment on Newegg posted by a frustrated owner indicates that it is only compatible with 4-core processors.
No, X9DR3-LN4F+ is compatible with all E5-2600 series processors that are 135W or less. And make sure it has the latest BIOS for the latest CPU microcode.