User Guide

2-2 Chapter 2
2.2. System Memory
• 64-bit Mode: Start populating DIMMs only at slot DIMM2, DIMM4,
DIMM6, and/or DIMM8.
• 128-bit Mode: Start populating in pairs and in order from DIMM1+DIMM2.
• At least one DIMM slot must be populated for the system to POST.
• For best performance, populate DIMMs symmetrically.
• To access DIMMs on CPU2, both processors must be installed.
CPU1 CPU2
DIMM1 DIMM2 DIMM3 DIMM4 DIMM5 DIMM6 DIMM7 DIMM8
X
X X
X X
X X X
X X X
64-bit mode
X X X X
X X
X X X X
X X X X
X X X X X X
X X X X X X
128bit mode
X X X X X X X X
SU-2S