Specifications

Chapter 2. Architecture and technical overview 79
Table 2-27 lists the available InfiniBand adapters.
Table 2-27 Available asynchronous adapters
2.9 Internal storage
Serial Attached SCSI (SAS) drives the Power 770 and Power 780 internal disk subsystem.
SAS provides enhancements over parallel SCSI with its point-to-point high frequency
connections. SAS physical links are a set of four wires used as two differential signal pairs.
One differential signal transmits in one direction. The other differential signal transmits in the
opposite direction. Data can be transmitted in both directions simultaneously.
The Power 770 and Power 780 CEC enclosures have an extremely flexible and powerful
backplane for supporting hard disk drives (HDD) or solid-state drives (SSD). The six small
form factor (SFF) bays can be configured in three ways to match your business needs. There
are two integrated SAS controllers that can be optionally augmented with a 175 MB Cache
RAID - Dual IOA Enablement card (Figure 2-22 on page 81). These two controllers provide
redundancy and additional flexibility. The optional 175 MB Cache RAID - Dual IOA
Enablement Card (#5662) enables dual 175 MB write cache and provides dual batteries for
protection of that write cache.
There are two PCIe integrated SAS controllers under the POWER7 I/O chip and also the SAS
controller that is directly connected to the DVD media bay (Figure 2-22 on page 81).
Power 770 and Power 780 supports various internal storage configurations:
򐂰 Dual split backplane mode: The backplane is configured as two sets of three bays (3/3).
򐂰 Triple split backplane mode: The backplane is configured as three sets of two
bays (2/2/2).
򐂰 Dual storage IOA configuration using internal disk drives (Dual RAID of internal drives
only): The backplane is configured as one set of six bays.
򐂰 Dual storage IOA configuration using internal disk drives and external enclosure (Dual
RAID of internal drives and external drives).
Configuration options will vary depending on the controller options and the operating system
selected. The controllers for the dual split backplane configurations are always the two
embedded controllers. But if the triple split backplane configuration is used, the two integrated
SAS controllers run the first two sets of bays and require a #5901 PCIe SAS adapter located
in a PCIe slot in a CEC enclosure. This adapter controls the third set of bays. By having three
controllers, you can have three boot drives supporting three partitions.
Feature
code
CCIN Adapter description Slot Size OS
support
#2728 57D1 4-port USB PCIe adapter PCIe Short A, L
#5785 4-Port Asynchronous EIA-232 PCIe
adapter
PCIe Short A, L
#5289 2B42 2-Port Async EIA-232 PCIe adapter PCIe Short A, L