Pci Expansion Devices - Silicon Graphics Origin 350 User Manual

PCI Expansion Devices

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A compute module contains four PCI/PCI-X slots; however, the base compute module
has only two PCI/PCI-X slots and one PCI slot available because the lowermost slot is
reserved for the IO9 PCI 66 MHz card, and the slot immediately above where the IO9
card is installed can only support PCI cards that run at a speed of 66 MHz or slower.
You can expand your I/O capabilities by adding PCI expansion devices to your system
to increase the amount of PCI/PCI-X and PCI slots.
Two types of PCI expansion devices are available: the MPX module and the PCI
expansion module. Both modules are peer-attached devices; they connect to the NI
(network interface) port of the compute module's Bedrock ASIC via the compute
module's NUMAlink connector or via the NUMAlink module.
The MPX module is a 2U AC-powered device that has four PCI/PCI-X slots (see
Figure 2-11 on page 86). In a base configuration that contains one compute module, you
can add one MPX module to your system. In a NUMAlink configuration, you can add up
to four MPX modules. See Chapter 4, "Memory and PCI Expansion (MPX) Module," for
more information about the MPX module.
The PCI expansion module, shown in Figure 2-12, contains six PCI buses (buses 1
through 6) that can seat as many as twelve PCI cards. Each bus has two PCI slots (see
Figure 2-13 on page 89) that are labeled 1 and 2.
There are two versions of the PCI expansion module: one version has 12 slots that
support 3.3-V or universal PCI cards, and the other version has 6 slots that support 5-V
or universal PCI cards and 6 slots that support 3.3-V or universal PCI cards.
In the base configuration and in a NUMAlink configuration, the PCI expansion module
must be paired with a compute module. Therefore, follow these guidelines:
• In a base configuration that contains one compute module, you can add one PCI
expansion module to your system.
• In a NUMAlink configuration, you can add one to four PCI expansion modules to
your system. The following rules indicate how many PCI expansion modules you
can add to your system:
• You can add one PCI expansion module to a system that contains two to seven
compute modules.
System Components
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