Sunfire V480 Administration Manual page 19

There are eight DIMM slots per processor; 16 slots per dual processor/memory module. The eight DIMM slots are
arranged as two memory groups of four slots per processor. Each processor may have a different amount of memory.
Configuration requirements state:
DIMMs must be added in groups of four (no partially populated groups)
All four DIMMs in any group must be of identical capacity
The minimum memory configuration per dual processor/memory module is eight DIMMs, four in each memory
subsystem (four per processor)
Memory interleaving is a function of the number of DIMMs and their capacity relative to the other memory groups on the
dual processor/memory module. Interleaving is implemented on a 64 byte boundary to coincide with the width of the
memory data bus. The level of interleaving is implemented as:
8 DIMMs 4-way if all DIMMs are identical;
otherwise 2-way
12 DIMMs 4-way between any two groups configured identically
2-way on each group, otherwise
16 DIMMs 8-way if all DIMMS are identical
4-way between any two groups configured identically
2-way on each group that does not match any other group.
If successive accesses alternate between two distinct logical groups, the sustainable bandwidth is 1.6 GB/sec. When the
access pattern involves four logical groups, the sustainable bandwidth is 2.4 GB/sec.
The currently supported memory options are:
1 GB Memory Expansion (4 x 256 MB DIMMs)
2 GB Memory Expansion (4 x 512 MB DIMMs)
4 GB Memory Expansion (4 x 1 GB DIMMs),
The memory subsystem is capable of supporting up to 4 GB per memory group which would allow a total capacity of 32
GB with a 4-way system.
TM
Sun Fire V480 Server
Just the Facts
Sun Proprietary and Confidential - Internal Use Only
Sept. 26, 2002
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