IBM eServer 370 xSeries, User Reference Manual

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Installing DIMMs and memory boards
You can increase the amount of memory in your server by installing additional dual
inline memory modules (DIMMs) . Your server uses 100 MHz, 168-pin, PC100
registered synchronous dynamic random-access memory (SDRAM),
industry-standard DIMMs with error checking and correction (ECC). You can add
extra DIMMs or replace existing DIMMs.
Notes:
1. You can install an optional memory board that contains an additional 16 DIMM
connectors and supports cache-line interleaving. To obtain an optional memory
board, contact an IBM reseller or IBM marketing representative.
2. The connector identifiers on both the standard and the optional memory boards
are J1–J16. To distinguish the two memory boards, use the labels provided on
the processor housing assembly. These labels refer to the connector identifiers
as A1–A16 on the standard memory board (A), and B1–B16 on the optional
memory board (B).
3. Your server comes with a system label on the server cover. The numbers
located to the right of the memory boards on the system label do not indicate
DIMM connector identifiers. These numbers indicate the DIMMs; for example,
1
means the first DIMM that you install,
9
means the ninth DIMM that you
install, and so on.
4. Cache-line interleaving can occur only if two memory boards are installed in the
server. This process allows the two memory boards to share a common
address range, with one memory board responding to even-numbered cache
lines, and the other memory board responding to odd-numbered cache lines.
This configuration has the highest performance because it allows the two
SDRAM arrays to be used in a balanced fashion, reducing access conflicts.
5. Installing or removing DIMMs changes the server configuration. Therefore,
after installing or removing a DIMM, save the new configuration information in
the Configuration/Setup Utility program. See “Using the Configuration/Setup
Utility main menu” on page 21 for more information.
6. If you replaced a defective DIMM, you must manually enable the DIMM slot in
the Configuration/Setup Utility program. In this case, the system does not
automatically access the Configuration/Setup Utility program to enable the
DIMM slot. See “Memory settings” on page 30 for additional information.
7. To verify the correct amount of memory installed in your server, review the
information on the Logo screen during system startup. The operating system
might not reflect the correct amount of memory.
8. See “Memory board component locations” on page 105 for a layout of the
memory board.
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xSeries 370 User's Reference