How do I understand the prtdiag -v memory interleaving output?      

Ultra Enterprise servers (UEXX00) have the ability to use memory
interleaving.  Memory interleaving can be viewed by the prtdiag 
command.  

	/usr/platform/sun4u/sbin/prtdiag -v 

The following explains how to read the prtdiag output.

First you need to understand that you have possibility of 1-Way, 2-Way,
4-Way and 8-Way interleaving.  In order to have any of the above
memory interleaving groups, your memory boards must be the same size 
in each bank. Memory interleaving will group same size memory banks 
together.  

Your memory banks should be installed by installing them in
bank 0 on all systems boards.  Once ALL memory boards' bank0 are full 
then you should fill bank1 starting on memory board 0.  Larger banks 
must be installed 1st for best performance.

Below are several examples of prtdiag outputs.


*************************EXAMPLE #1***************************
========================= Memory =========================

                                              Intrlv.  Intrlv.
Brd   Bank   MB    Status   Condition  Speed   Factor   With
---  -----  ----  -------  ----------  -----  -------  -------
 0     0    1024   Active      OK       60ns    8-way     A
 0     1    1024   Active      OK       60ns    8-way     A
 2     0    1024   Active      OK       60ns    8-way     A
 2     1    1024   Active      OK       60ns    8-way     A
 4     0    1024   Active      OK       60ns    8-way     A
 4     1    1024   Active      OK       60ns    4-way     B
 5     0    1024   Active      OK       60ns    8-way     A
 5     1    1024   Active      OK       60ns    4-way     B
 6     0    1024   Active      OK       60ns    8-way     A
 6     1    1024   Active      OK       60ns    4-way     B
 7     0    1024   Active      OK       60ns    8-way     A
 7     1    1024   Active      OK       60ns    4-way     B



In the above example you have 12 banks all 1024MB in size.  Since
you have maximum possible 8-Way this will leave 4 more banks to 
have addition 4-Way.  Thus group A = 8-Way and Group B = 4-Way.


Memory Board#	Memory Bank0	Memory Bank1
=============================================

0		    A		    A
2		    A		    A
4		    A		    B
5		    A		    B
6		    A		    B
7		    A		    B


***************************************************************

*************************EXAMPLE #2***************************


========================= Memory =========================

                                              Intrlv.  Intrlv.
Brd   Bank   MB    Status   Condition  Speed   Factor   With
---  -----  ----  -------  ----------  -----  -------  -------
 0     0     256   Active      OK       60ns    4-way     A
 0     1     256   Active      OK       60ns    4-way     A
 2     0     256   Active      OK       60ns    4-way     A
 2     1     256   Active      OK       60ns    1-way     B
 4     0     256   Active      OK       60ns    4-way     A


In this example you have 5 banks all the same size.  So you will
have 4-Way and 1-Way.  The 1st group of 4-Way will be grouped
using Bank 0 on all system boards.  Then it will add bank1
from memory board 0 to complete a 4-Way.  Leaving only 1 bank
left will make a 1-Way on bank1 of board#2.  Below you see how
the system groups them.


Memory Board#	Memory Bank0	Memory Bank1
=============================================

0		    A		    A
2		    A		    B
4		    A		     


***************************************************************

*************************EXAMPLE #3***************************


========================= Memory =========================

                                              Intrlv.  Intrlv.
Brd   Bank   MB    Status   Condition  Speed   Factor   With
---  -----  ----  -------  ----------  -----  -------  -------
 0     0    1024   Active      OK       60ns    4-way     A
 0     1     256   Active      OK       60ns    4-way     B
 2     0    1024   Active      OK       60ns    4-way     A
 2     1     256   Active      OK       60ns    4-way     B
 4     0    1024   Active      OK       60ns    4-way     A
 4     1     256   Active      OK       60ns    4-way     B
 6     0    1024   Active      OK       60ns    4-way     A
 6     1     256   Active      OK       60ns    4-way     B



In this example you have 8 banks.  But it will not group them
in a single 8-Way bank because of the 2 difference sizes of
banks.  So the 4 banks of 1024MB will be a 4-way.  Then the 4
banks of 256MB will be a 2nd 4-way.  Below you can see how
it groups them.



Memory Board#	Memory Bank0	Memory Bank1
=============================================

0		    A		    B
2		    A		    B
4		    A		    B
6		    A		    B

***************************************************************