IBM xSeries 380, Hardware Maintenance Manual

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Diagnostics
81
The first line is the total memory installed (regardless of condition). The second line is
the total memory usable (and is less than the first line, only if defective DIMMs were
found). The third line counts the memory as the test is being performed. When the
test is completed, the number in this line should equal the number in the second line.
A fourth line, "Memory Errors Detected", will occur only if the memory test found
errors on this latest test pass. It will not occur if the memory test found errors on
previous boots; however, in that case, the size in the second line will be smaller than
the first line.
Note: There is a 2 GB fixed gap between the memory address 2 GB to 4 GB, which is
occupied by PCI gap, system flash address, and other fixed addresses. This 2
GB of memory address space will not be available for ’Configured’ memory.
For example, if a system has total installed memory of 64 GB, the maximum
usable memory in the system will be (64 GB - 2 GB) = 62 GB. In this case, the
"Configured" line will read 62 GB. As mentioned above, the "Tested" line will
count up and its final value will always be equal to the "Configured" line
(assuming all the memory is good, this will be 62 GB in this example). Please
refer to the 82460GX Chipset EDS for further details on the system memory
map.
A second set of messages will be seen later in the POST, which indicates where the
memory test found errors. The sequence is as follows:
Error in memory subsystem: (Lower/Upper) Board, DIMM XX
ERRORS FOUND IN MEMORY SUBSYSTEM. FAILING ROWS WILL BE MAPPED OUT ON THE
NEXT RESET. IT IS STRONGLY SUGGESTED THAT YOU RESET THE SYSTEM NOW.
ALLOWING THE SYSTEM TO CONTINUE TO BOOT MAY RESULT IN UNSTABLE SYSTEM
BEHAVIOR AND/OR HARD DISK CORRUPTION.
Hit <F1> to load defaults or <F2> to run SETUP or <ESC> to continue
Important: Failure to reset the system as explained above may cause damage to your
system.
The following examples assume that the total memory installed is 32 GB (32768 MB).
Example #1: The system boots with 32 GB of memory installed and, no defects found,
will report the following:
32768 MB Total Memory Installed
32768 MB Configured
32768 MB Tested
Example #2: Consider a system populated that has the entire upper board memory
slots with 1 GB DIMMs. The first row test and the base row test passed without
errors. The extended memory test detected a memory error in DIMM 17. The
following messages will appear:
32768 MB Total Memory Installed
32768 MB Configured
32768 MB Tested
Memory Errors Detected
A second set of messages will be seen later in the POST that indicates where the
memory test found errors. The sequence is as follows:
8C81: Error in memory subsystem: Upper Board, DIMM 17