For a single processor, they must be in slots 1 and 2.  They should be labeled on the board too, but: [IMAGE] Optimizer Mode is easily found and enabled in the BIOS Setup (F2), under Memory.
Hi I removed 4 * 2Gb DIMMS form my poweredge and replaced it with 2 * 16GB Dimms The op system finds the memory ok Windows 2008 64bit but the bios does not like the configuration - when it goes through the boot process it suggest a slot configuration which I have tried and that does not work  I have posted before and someone suggested I read the manual which I have and that is not clear, I just need a simple explanation  of which slots I should use and and bios setting I need to do to complete the  task   Regards  J 
PowerEdge T410