#4449 8 GB DDR-1 Main Storage 520/550

IBM 4449 - 8 GB DDR Main Storage (DDR1; 128 Mb technology, stacked, CCIN 30D5) (ships four 2 GB DIMMs for a total of 8 GB)

For a iSeries model 520 or 550, install DIMMs in sets of four (quads) with one exception: A single pair of 256 MB DIMMs is allowed on the #8950 processor. Add an additional pair of 256 MB DIMMs to the original pair (to make a quad) whenever more DIMMs are added. Then one additional quad of DIMMs can be added to the system. For the #8950 processor, the first DIMM pair goes into DIMM slots J0A and J2A. The second pair of DIMMs goes into slots J0C and J2C. The first quad of DIMMs is plugged into DIMM slots J0A, J2A, J0C, and J2C. The second quad of DIMMs is plugged into DIMM slots J0B, J2B, J0D, and J2D.

For a model 550, install DIMMs in sets of four (quads). The 550 has two processor cards and best memory access performance is achieved when memory is balanced on each processor card:

• Plug the first quad of memory modules into memory module slots P1-C8-C1, P1-C8-C3, P1-C8-C6, and P1-C8-C8 on each processor card, or slots P1-C9-C1, P1-C9-C3, P1-C9-C6, and P1-C9-C8 on each processor card.
• Plug the second quad of memory modules into memory module slots P1-C8-C2, P1-C8-C4, P1-C8-C5, and P1-C8-C7 on each processor card or, slots P1-C9-C2, P1-C9-C4, P1-C9-C5, and P1-C9-C7 on each processor card.