Compaq AlphaServer ES45 Service Manual page 220

Memory Performance Considerations
Interleaved operations reduce the average latency and increase the memory
throughput over non-interleaved operations. With one memory option
(4 DIMMs) installed, memory interleaving will not occur. For 2-way
interleaving, array 0 & 2 and 1 & 3 must have the same size memory. For 4-way
interleaving, array 0 through 3 must have the same size memory.
The output of the show memory command provides the memory interleaving
status of the system.
P00>>> show memory
Array Size
--------- ----------
0 4096Mb
1 1024Mb
2 4096Mb
3 1024Mb
10240 MB of System Memory
The show memory display does not indicate the number of DIMMs or their
size. Array 3 could consist of two sets of 128 MB DIMMs (eight DIMMs) or one
set of 256 MB DIMMs (four DIMMs). Either combination provides 1024 MB of
memory.
For optimum memory utilization and performance, load memory arrays in the
following order: 0, 1, 2, 3, 4, 6, 5, and 7. See Figure 6–4 for array locations.
6-26 ES45 Service Guide
Base Address Intlv Mode
---------------- ----------
0000000000000000
0000000200000000
0000000100000000
0000000240000000
2-Way
2-Way
2-Way
2-Way