The Silicon Graphics Onyx4 UltimateVision system is a high-performance visualization system running the SGI IRIX operating system. The platform is available in a number of configurations to meet your visualization requirements.
This chapter introduces the two graphics bricks used in the Onyx4, and provides an overview of their connection to the rest of the platform.
The SGI Onyx4 system uses two bricks for graphics output: a graphics-only brick (called a G2-brick) and a graphics/node brick (called a G2N-brick).
The G2-brick is a 2U rack mountable enclosure containing two high-performance graphics pipes. This brick connects as an I/O device.
The G2N-brick is a 2U rack mountable enclosure which, in addition to the two high-performance graphics pipes, adds to the host system a node board with two or four CPUs and up to eight memory DIMMs. This brick connects as an integral part of the host system's compute fabric. Though it contains CPUs and memory, the G2N-brick does not have boot I/O functionality, and therefore may not be used as a standalone system.
Though internally different, the G2-brick and the G2N-brick may not be distinguished by external features.
The G2-brick is a graphics-only I/O brick, and therefore connects to a host system using XIO.
The G2N-brick is a compute brick, and therefore connects to the host system using NUMAlink, either directly or through a NUMAlink module (router). This way the brick becomes an integral part of the host computer, and contains both CPUs and memory, in addition to graphics output capabilities.
The sections below show front, rear, and internal views of the SGI Onyx4 G2-bricks and G2N-bricks.
This section describes the front panel controls and indicators of the G2-bricks and G2N-bricks, as shown in Figure 1-1.
The front panels of the G2-brick and G2N-brick have the following items:
L1 controller display. A liquid crystal display (LCD) that shows status and error messages generated by the L1 controller.
Note: Refer to the SGI L1 and L2 Controller Software User's Guide (007-3938-00x) for more information on the L1 controller. Status LEDs. The front panel has the following LEDs:
Power button LED. This LED illuminates green when the internal components are on.
Service-required LED. This LED illuminates yellow to indicate that an item is not functioning properly (for example, a fan is off), but the system is still operating.
Failure LED. This LED illuminates red to indicate that a failure has occurred and the system is down.
Power button. Press this button to power on the system. Alternatively, you can power on the system at a system console.
Reset button. Press this button to reset the internal processors and ASICs. The reset will cause a memory loss.
NMI button. Press this button to issue a non-maskable interrupt command to a brick. If the system hangs, you can send the affected brick an NMI interrupt. The interrupt goes to PROM and causes the CPU state to be captured for that brick. This information is saved in flash PROM and in the system log, and can assist SGI technicians in debugging system hangs and customer problems.
Figure 1-2 shows a view of the rear panel of an SGI Onyx4 G2-brick and G2N-brick.
The rear panel of the SGI Onyx4 G2-brick and G2N-brick has the following items:
AC power input. This connector connects the graphics brick to an AC power outlet.
Serial console port. This DB–9 serial port (console and diagnostic port) enables you to connect a system console to the L1 controller on the graphics brick.
L1 USB port. This universal serial bus (USB) type B port connects the graphics brick L1 controller to an L2 controller.
XIO connector. This Crosstown2 connector connects the G2-brick to a host system compute brick. This connection is made with a NUMAlink cable at 800 MB/s in each direction.
XIO connector LEDs. The XIO connector has a yellow LED and a green LED (both located to the right of the NUMAlink connector). The yellow LED indicates that both the graphics brick and the host system brick to which it is connected are powered on. The green LED indicates that the host system has established a link to the graphics brick.
ImageSync connectors. These connectors are used in conjunction with an SGI ImageSync card.
NUMAlink connector (only used in G2N-bricks). This NUMAlink connector connects the G2N-brick to the host system. This connection is made with a NUMAlink cable at 1.6 GB/s in each direction.
NUMAlink LEDs. The NUMAlink connector has a yellow LED and a green LED (both located to the right of the NUMAlink connector). The yellow LED indicates that both the graphics brick and the host system brick to which it is connected are powered on. The green LED indicates that the host system has established a link to the graphics brick.
DVI-I display connectors. These connectors are used to attach one or more external displays.
Stereo Sync connectors. These connectors are used to attach stereo sync devices.
Figure 1-3 shows an internal view of the SGI Onyx4 G2N-brick.
