IBM eServer 250 xSeries, User Reference Manual, Page: 80 / 186

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IBM® xSeries 250: User’s Reference
Installing memory-module kits
Before you continue with the memory-installation procedure, review the following:
• Review the information in“Before you begin” on page 36 through “Safety
information statements” on page 38.
• All the DIMMs installed in each set must be the same size and speed, but all the
sets do not have to contain DIMMs of the same size and speed.
• The memory board contains 16 DIMM connectors and supports 4-way memory
interleaving.
• Install only 3.3 V, 168-pin, 8-byte, registered DIMMs. Only 100 MHz, 72-bit,
registered, synchronous, error correcting code (ECC), SDRAM configuration
DIMM memory is supported for the 128 MB, 256 MB, 512 MB and 1 GB (when
available) DIMMs.
Note: If you install 64 MB DIMMs, they will not support the Chipkill memory
function.
• If you install 4 GB of memory, some of the memory is reserved for system
resources. The amount reserved for system resources depends on the
configuration of the server.
• If you install 16 GB of memory, the Configuration/Setup Utility will display the
memory that is usable by the network operating system. This amount of memory
might differ from the amount of memory that you have installed.
• Installing or removing DIMMs changes the configuration information in the
server. Therefore, after installing or removing a DIMM, you must save the new
configuration information using the Configuration/Setup Utility program. Refer
to “Using the Configuration/Setup Utility program” on page 13 for more
information.
• Install the DIMMs in the order provided in Table 3 on page 67.