Hi,   Based on the user guide, you may need to populate the white tab first then black tabs and lastly green tabs. Therefore, please populate the white tabs first with the available memory you have, then the remaining to the black tabs. Also please make sure the iDRAC and BIOS is up to date with the latest firmware.    Reference: [URL]
I am upgrading my Poweredge R630 with 10x32GB RAM, and have removed existing RAM in server which will not be used.The server has 2 x E2680v4 CPUsWhich are the correct memory channels to place 10 x 32GB RAM into.The examples shown in the Owner's manual for 2 CPU's only show 8x32GB and 12x32GB.
Dell R630 RAM upgrade and memory channels