SRDB ID: 21869
SYNOPSIS: How to read prtdiag memory interleaving on Ultra servers
DETAIL DESCRIPTION:
How do I understand the prtdiag -v memory interleaving output?
SOLUTION SUMMARY:
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
***************************************************************
APPLIES TO: Hardware, Hardware/Ultra Enterprise/Servers, AFO Vertical Team Docs, AFO Vertical Team Docs/Hardware
ATTACHMENTS: