IBM xSeries 235, Maintenance & Troubleshooting

Page: 87 / 214

Installing memory modules
Adding memory to your server is an easy way to make programs run faster. You
can increase the amount of memory in your server by installing memory-module
options. When you install memory, you must install a pair of matched dual inline
memory modules (DIMMs).
Notes:
1. The system board contains 6 DIMM connectors and supports two-way memory
interleaving.
2. The DIMM options available for your server are 128 MB, 256 MB, 512 MB, and
1 GB. Your server supports a minimum of 256 MB and a maximum of 6 GB of
system memory.
3. The amount of usable memory will be reduced depending on the system
configuration. A certain amount of memory must be reserved for system
resources. The BIOS will display the total amount of installed memory and the
amount of configured memory.
4. Your server comes with two 128 MB or 256 MB DIMMs, (for a total of 256 MB
or 512 MB memory) installed in the DIMM 5 and DIMM 6 memory connectors
(J14 and J15, respectively). When you install additional DIMMs, be sure to
install them in pairs, with the next pair in DIMM connectors 3 and 4 (J11 and
J12), and the final pair in DIMM connectors 1 and 2 (J7 and J9).
5. Each DIMM in a single pair must be the same size, speed, type, and
technology. You can mix compatible DIMMs from various manufacturers.
6. Each DIMM pair does not have to contain DIMMs of the same size, speed, type,
and technology as the first pair.
7. Install only 133 MHz, 2.5 V, 184-pin, double-data-rate (DDR), PC2100,
registered synchronous dynamic random-access memory (SDRAM) with error
correcting code (ECC) DIMMs. These DIMMs must be compatible with the latest
PC2100 SDRAM Registered DIMM specification. For a list of supported options
for your server, go to http://www.ibm.com/us/compat/ on the World Wide Web.
8. Your server supports Chipkill
™
memory if the DIMMs are all type x4 and are
larger than 128 MB. Using any 128 MB DIMMs, or DIMMs that are not type x4,
on your server disables Chipkill memory.
9. You do not need to save new configuration information when installing or
removing DIMMs. The only exception is if you replace a faulty DIMM that was
marked as
Disabled in the Memory Settings menu. In this case, you need to
re-enable that memory row in the Configuration/Setup Utility or reload the
default memory settings (see “Choices available from the Configuration/Setup
main menu” on page 12).
Install the DIMMs in the order shown in the following table.
Table 7. DIMM installation sequence
Pair DIMM connectors Diagnostic reference
First 6 and 5 (J15, J14) Bank 3
Second 4 and 3 (J12, J11) Bank 2
Third 2 and 1 (J9, J7) Bank 1
Chapter 4. Customer replaceable units
77