Memory Modules; Figure 4-21 Memory Module Groups 0 And 1 - Sun Microsystems Netra 440 Service Manual

Memory Modules

The Netra 440 server uses 2.5-volt, high-capacity double data-rate dual inline
memory modules (DDR DIMMs) with error-correcting code (ECC). The system
supports DIMMs with 512-Mbyte and 1-Gbyte capacities.
Within each CPU/memory module, the four DIMM slots are organized into groups
of two. The system reads from, or writes to, both DIMMs in a group simultaneously.
DIMMs, therefore, must be added in pairs. The figure below shows the DIMM slots
and DIMM groups on a Netra 440 server CPU/memory module. Adjacent slots
belong to the same DIMM group. The two groups are designated 0 and 1.
0 1
Memory Module Groups 0 and 1
FIGURE 4-21
You must physically remove a CPU/memory module from the system before you
can install or remove DIMMs. The DIMMs must be added in pairs within the same
DIMM group, and each pair used must have two identical DIMMs installed—that is,
both DIMMs in each group must be from the same manufacturing vendor and must
have the same capacity (for example, two 512-Mbyte DIMMs or two 1-Gbyte
DIMMs).
Note – Each CPU/memory module must be populated with a minimum of two
DIMMs, installed in either group 0 or group 1.
Chapter 4 Removing and Replacing Cold-Swappable Components 81