Memory Requirements - IBM pSeries 690 Service Manual

Memory Requirements

Note: The configuration of a system that was ordered with memory Capacity Upgrade on Demand
(CUoD) features will appear slightly different than the configuration in this discussion.
When the system is ordered, the installed memory is positioned according to the following guidelines:
v The pSeries 690 has eight memory slots. Four memory slots use inward-facing memory cards and four
use outward-facing memory cards. The inward-facing memory slots are used by the first and second
processor module positions, while the outward-facing memory slots support the third and fourth 8-way
processor module positions.
v A pSeries 690 system with only one processor MCM position populated has access to only two
inward-facing memory slots.
v Minimum system memory is 8 GB. Maximum system memory is 512 GB.
v Memory is available in 4 GB, 8 GB, 16 GB, 32 GB, and 64 GB inward-facing and outward-facing
increments.
v The following memory configuration considerations are recommended to ensure the optimum
performance is obtained for the system:
– Memory should be installed in identical pairs.
– All available memory locations should be populated with memory cards.
– Memory sizes should be balanced as closely as possible across all populated MCM locations.
v The number of active memory book slots in a system is related to the number of populated MCM
locations. Two memory book slots are activated with each MCM that is installed.
– The first MCM installed activates the first and second inward-facing memory positions.
– The second MCM installed activates the third and fourth inward-facing memory positions.
– The third MCM installed activates the first and second outward-facing memory positions.
– The fourth MCM installed activates the third and fourth outward-facing memory positions.
v It is recommended that all systems have access to a 4-mm or 8-mm tape drive for submission of
system dump information, if required. This function can be accomplished through locally attached or
network-attached devices as appropriate.
64 Eserver pSeries 690 Service Guide