IBM 755 - Manual (Page 24)

IBM United States Hardware Announcement
110-008
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Power cords
Two power cords are required.
The Power 755 requires 200-240 V power cords for all configurations.
System memory
• A minimum 128 GB of memory is required on the Power 755 system.
• Eight memory DIMM slots are on a processor card. The maximum system memory
is 256 GB with four processor cards.
• Different system memory feature numbers may not be mixed on the same
processor card. However, a system with more than one processor card may use
different memory feature numbers on the same system.
• Memory must be installed in groups of one feature (two DIMMs), two features
(four DIMMs), or four features (eight DIMMs) per processor card. Installation of
three features (six DIMMs) is not permitted.
• It is generally recommended that memory be installed evenly across all processor
cards in the system. Balancing memory across the installed processor cards allows
memory access in a consistent manner and typically results in the best possible
performance for your configuration. However, balancing memory fairly evenly
across multiple processor cards, compared to balancing memory exactly evenly
typically has a very small performance difference.
Plans for future memory upgrades should be taken into account when deciding which
memory feature size to use at the time of initial system order.
Figure 1. Memory features
Feature Minimum Maximum
Feature number quantity quantity
8 GB 1066 MHz 4526 0 16
(2 x 4 GB RDIMMs)
16 GB 1066 MHz 4527 0 16
(2 x 8 GB RDIMMs)
Note: The 8 GB memory feature (#4526) is planned to be available on March 16,
2010.
Drawer/tower attachment:
• EXP12S SAS DASD Expansion Drawer (#5886)
– Feature number 8340 supports one feature number 5886 drawer directly off the
system unit's SAS port. EXP12S drawers are attached to a PCI-X or PCIe SAS
adapter via SAS cables.
– A system maximum of 13 is allowed.
The following list shows I/O drawers that are supported or available on the 8236
machine type and the correct interface to use for each of the drawers.
Order
Feature Description Status Interface
5886 Exp 12S SAS
Disk Drawer Available SAS
Maximum number of attached I/O drawers per system:
Power 755
Feature (32-core)