Chapter 8. R-brick

This chapter describes the function and physical components of the optional R-brick in the following sections:


The R-brick (router brick) is an eight-port optional router that functions as a high-speed switch to route network packets from one CR-brick to another throughout the NUMAlink interconnect fabric. Figure 8-1 shows a front view of the R-brick.

The key component within the R-brick is the router chip, an SGI custom-designed ASIC. The router chip is an eight-port crossbar that connects any input-link channel to any of the seven possible output-link channels.

Figure 8-1. Front View of the R-Brick

Front View of the R-Brick

The R-brick has the following features:

  • Eight NUMAlink channels

  • One USB port for system controller support

  • One L1 controller and LCD display

  • Two hot-pluggable cooling fans

Figure 8-2 shows a block diagram of the R-brick.

Figure 8-2. R-brick Block Diagram

 Block Diagram

External Components

This section describes the external components that are located on the front and rear panels of the R-brick.

Front Panel Components

The R-brick contains the following front panel items (as shown in Figure 8-1):

  • L1 display. The L1 display is a 55.7 mm X 32 mm backlit liquid crystal display (LCD) that displays system messages. It displays two lines with a maximum of 12 characters on each line.

  • On/Off switch with LED. Press this button to turn on the R-brick internal components. You can also turn on the R-brick internal components at a system console.

  • Three LEDs:

    • On/Off switch LED. This LED illuminates green when the R-brick internal components are on and turns off when they are off.

    • Service required LED. This LED illuminates orange to indicate that an item is broken or not operating properly (for example, a fan is off), but the R-brick is still operating.

    • Failure LED. This LED illuminates red to indicate that a system failure has occurred and the R-brick is down.

  • Fans. Two hot-pluggable fans provide N+1 redundant cooling.

Rear Panel Components

The R-brick has the following rear panel items (see Figure 8-3):

  • Power switch. Move the power switch to the I position to power on the L1 controller within the R-brick, and to the 0 position to power off the L1 controller. Powering on the L1 controller Illuminates the 12-VDC LED green.

  • PWR (power) connector. This connects the R-brick to the power bay, to provide 12-VDC and 48-VDC power to the R-brick.

  • 48-VDC and 12-VDC LEDs. The power switch must be in the ON (I) position for these LEDs to be on. The 12-VDC LED illuminates green when the L1 controller is powered on and operating, and the 48-VDC LED illuminates green when the rest of the R-brick internal components are powered on and operating. You power on the internal components by pressing the On/Off switch on the L1 controller panel.

  • Links R TO R connectors (1, 6, 7, and 8, or A, F, G, and H). These link connectors connect the R-brick to other R-bricks in the network fabric.

  • Links R to R and CR to R connectors (2, 3, 4, and 5 or B, C, D, and E). These link connectors normally connect the R-brick to CR-bricks; however, in larger systems they are also used to connect R-bricks to R-bricks.

  • L1 port connector. This connects the internal USB hub of the R-brick to an optional console/controller. The internal USB hub can receive the USB signals from the controller via this port and distribute these signals to the L1 of the R-brick.

  • Link connector LEDs. Each NUMAlink connector has two LEDs, as follows:

    • The yellow LED illuminates to indicate that both the R-brick and the brick to which it is connected are powered on.

    • The green LED illuminates when a link has been established between the R-brick and the brick to which it is connected.

      Figure 8-3. Rear View of R-brick

      Rear View of R-brick

Technical Specifications

Table 8-1 lists the technical specifications of the R-brick.

Table 8-1. R-brick Technical Specifications




3.3 in. (83.82 mm)


17.38 in. (441.45 mm)


27.5 in. (698.50 mm)


20 lb (9.1 kg)

Input power

 48 VDC (~ 60 W)

Table 8-2 lists the specifications of the R-brick ports.

Table 8-2. R-brick Port Specifications



Peak Transfer Rate



 3.2 GB/s each direction



12 Mbits/s