For servers based on the Intel plan of record
UPDATE: 06/30/2012: v1.21 – added 1333MHz/1600MHz speed info
UPDATE: 06/30/2012: v1.21_ibmsys_1_0 – IBM System x memory
UPDATE: 07/01/2012: v1.21_ibmsys_1_1 – IBM System x memory
UPDATE: 07/06/2012 – non-viability of LRDIMMs
UPDATE: 07/06/2012 – viability of HyperCloud
Here is a graphical illustration of how to choose memory for 2-socket Romley servers.