Installing a memory module

The following notes describe the types of dual inline memory modules (DIMMs) that the server supports and other information that you must consider when installing DIMMs:

vThe server supports industry-standard, 533/667 MHz, PC2-4200, double-data-rate 2 (DDR2) dual inline memory modules (DIMMs).

vThe system board contains four DIMM connectors and supports two-way memory interleaving.

vThe DIMM options available for the server are 512 MB, 1 GB, and 2 GB. The server supports a minimum of 512 MB and a maximum of 8 GB of system memory.

vThe server comes with one 512 MB DIMM or two 512 MB DIMMs installed.

Depending on the DIMM sizes that you select, the server also supports two or four DIMMs. The 512 MB DIMM option kit contains one DIMM; however, the 1 GB DIMM and 2 GB option kits each contain two DIMMs.

vThe amount of usable memory will be reduced depending on the system configuration. A certain amount of memory must be reserved for system resources. To view the total amount of installed memory and the amount of configured memory, run the Configuration/Setup Utility program and select System Summary from the menu. For additional information, see the User’s Guide on the IBM xSeries Documentation CD.

vFor two-way memory interleaving, DIMMs must be installed in matched pairs.

If one DIMM is installed in the DIMM 1 connector, when you install an additional DIMM, it must be installed in the DIMM 3 connector, and it must be the same size, speed, type, and technology as the DIMM in the DIMM 1 connector. You can mix compatible DIMMs from various manufacturers.

If you install a second pair of DIMMs in the DIMM 2 and DIMM 4 connectors, they do not have to be the same size, speed, type, and technology as the DIMMs in the DIMM 1 and DIMM 3 connectors. However, the size, speed, type, and technology of the DIMMs that you install in the DIMM 2 and DIMM 4 connectors must match each other.

vInstall only 1.8 V, 184-pin, double-data-rate 2 (DDR2), 533/667 MHz, PC2-4200, unbuffered synchronous dynamic random-access memory (SDRAM) with error correcting code (ECC) DIMMs. These DIMMs must be compatible with the latest DDR2 533/667 MHz SDRAM unbuffered DIMM specification. For a list of supported options for the server, see http://www.ibm.com/servers/eserver/ serverproven/compat/us/; then, select your country and navigate to the list of options for the server.

vWhen you restart the server after adding or removing a DIMM, the server displays a message that the memory configuration has changed.

Chapter 2. Installing options 13