Sun Microsystems Sun Fire V490 Parts Installation And Removal Manual page 113

The figure below shows the DIMM slots and DIMM groups on a CPU/Memory
board. Every fourth slot belongs to the same DIMM group. The four groups are
designated A0, A1, B0, and B1.
A 0
B 0
A 1
A 0
Follow these configuration rules when installing memory:
DIMMs must be added four at a time within the same group of DIMM slots;
I
every fourth slot belongs to the same DIMM group.
Each group used must have four identical capacity DIMMs installed (for example,
I
four 512-Mbyte DIMMs or four 1-Gbyte DIMMs).
Chapter 4 Servicing the CPU/Memory Board and Related Components
A 0
B 1
B 0
A 1
A 0
B 1
B 0
A 1
B 1
B 1
B 0
A 1
85