IBM p5 590 System Handbook page 269

Footnotes
X = Standard; Supported
O = Optionally Available; Supported
- = Not Applicable
P = Processor Capacity Upgrade on Demand option
B = Capacity BackUp offering
M = Memory Capacity Upgrade on Demand option
OOP = On/Off Capacity on Demand for Processors option
OOM = On/Off Capacity on Demand for Memory option
R = Reserve Capacity on Demand option
SOD = Statement of General Direction announced
a Shared memory
b Per processor
c Using maximum number of I/O drawers
d Per processor card, processor book or Multichip Module
e Requires additional software; check on availability
f Statement of Direction for redundant service processor - 1H 2005
g More details on interface and adapter dependencies and their effect on
these maximums can be found in the IBM Sales Manual or the pSeries PCI
Adapter Placement manual available at:
http://publib16.boulder.ibm.com/pseries/en_US/infocenter/base/HW_pci_adp
_pl.htm
h Figures for DDR1 266 MHz memory; For DDR2 533 MHz memory, range is
8 GB to 128 GB
i Supported on DDR1 memory only
Appendix A. Facts and features reference
247