IBM eServer OpenPower 720, Technical Overview And Introduction

Page: 40 / 74

30
OpenPower 720 Technical Overview and Introduction
2.8 External I/O subsystem
This section describes the external I/O subsystem, the 7311 Model D20 I/O drawer that is
supported on the OpenPower 720 system.
2.8.1 I/O drawers
As described in Chapter 1, “General description” on page 1, the OpenPower 720 system has
five internal PCI-X slots, which is enough for average customer configurations. If more PCI-X
slots are needed to dedicate more adapters to a partition or to increase the bandwidth of
network adapters, up to eight 7311 model D20 I/O drawers can be added to the OpenPower
720 system.
The OpenPower 720 system contains a RIO-2 bus to connect the internal PCI-X slots through
the PCI-X to PCI-X bridges and support up to four external I/O drawers. To support more I/O
drawers in one OpenPower 720, a RIO-2 expansion card FC 1806 is needed occupying
PCI-X slot 5. The RIO-2 expansion card supports up to four additional I/O drawers.
2.8.2 7311 Model D20 I/O drawer
The 7311 Model D20 I/O drawer must have the RIO-2 loop adapter (FC 6417) to be
connected to the system. The PCI-X host bridge inside the I/O drawer provides two primary
64-bit PCI-X buses running at 133 MHz. Therefore, a maximum bandwidth of 1 GB/sec is
provided by each of the buses.
Figure 2-8 shows a conceptual diagram of the 7311 Model D20 I/O drawer subsystem.
Figure 2-8 Conceptual diagram of the 7311-D20 I/O drawer
Note: Because the OpenPower 720 has eight disk drive slots, customers performing
upgrades must perform appropriate planning to ensure the correct handling of their RAID
arrays.
R IO
133 M H z,
64-bit PC I-X
P C I-X Bridge
1 3
P C I-X H ost
B ridge
2
133 M H z, 64-bit P C I-X
4
6
4
/
1
3
3
6
4
/
1
3
3
6
4
/
1
3
3
6
4
/
1
3
3
P C I-X B ridge
5 6 7
6
4
/
1
3
3
6
4
/
1
3
3
6
4
/
1
3
3