  Try testing each DIMM in slot A1(One DIMM at a time).   Look at the system even/hardware log and the hardware>memory pane. Thanks
I'm upgrading a Dell R710 from single CPU to dual CPU with Xeon E5630 processors harvested from multiple R710 systems and combining into one. I have 18 2GB UDIMMs to play with, all from Dell configured R710 systems, but cannot get anything to POST beyond 3 sticks for each CPU.I have read the technical guide and the following two more comprehensive guides:Installing and Upgrading DDR3 Memory - Quick Reference GuideDell™ PowerEdge™ Servers 2009 - Memory - A Dell Technical White PaperI have concluded from this and other research the following:(1) The Xeon E5630 supports maximum memory speed of 1066MHz(2) UDIMM maximum is 24GB which I assume I can split between the CPUs for 12GB each(3) 2 DPC (DIMMs Per Channel), 3 Channels per CPUBut I cannot get this to work despite all the RAM working if I use 1 DPC for all 3 channels per CPU.It should work according to this chart:[IMAGE]with DIMM 0 and DIMM 1 each SINGLE rank as indicated and populated according to this:[IMAGE]with 3 Channels Used, 2 DPC using A1, A2, A3 and A4, A5, A6 for CPU 1 and B1, B2, B3 and B4, B5, B6 for CPU 2.The information gets a little scant about dual processors and think this may be where I'm hitting a limitation. How can I get 24GB of UDIMM running with dual CPUs?
Dell PowerEdge R710, Dual Xeon E5630, RAM upgrade: 12 x 2GB 1Rx8 UDIMMs won't 
POST