|C H A P T E R 4|
Sun Fire System Components
The Sun Fire 6800/4810/4800 systems share many of the same components. These components are the CPU/Memory boards, the I/O assemblies, the Repeater boards, and the System Controller boards. The Sun Fire 3800 system also shares the CPU/Memory boards, but uses different System Controller boards and I/O assemblies.
The CPU/Memory board is the same across the Sun Fire 6800/4810/4800/3800 systems. This board supports up to four UltraSPARC III CPU modules, eight Ecache SIMMs, and eight banks of memory, two bank per CPU with four DIMM sockets per bank, for a total of 32 DIMMs.
All DIMMs must be the same capacity and sizes within a bank and must not be intermixed on a board.
Two CPU/Memory board types are available, one with the UltraSPARC III 750-Mhz processor. The second board type has the UltraSPARC III 900-Mhz processor which will now be referred to as the CPU/Memory+ board.
Mixing CPU/Memory boards with CPU/Memory+ boards in the same chassis is not supported. You must install CPU/Memory boards of the same type (either CPU/Memory boards or CPU/Memory+ boards) in the same chassis. You cannot mix CPU/Memory boards in the same chassis. The CPU/Memory+ boards are not backward compatible with the CPU/Memory boards.
The Sun Fire 6800/4810/4800 systems support both PCI I/O and CompactPCI I/O devices. The Sun Fire 3800 system supports only CompactPCI I/O devices.
The I/O assemblies are logically and physically the same for the Sun Fire 6800/4810/4800 systems. The basic PCI I/O assembly will have six slots for standard PCI (33-MHz) device boards, plus two slots for PCI-66 (66-MHz) device boards.
The CompactPCI I/O assembly is designed for the CompactPCI form factor device boards. The Sun Fire 3800 system I/O assembly for CompactPCI supports a total of six slots. The Sun Fire 6800/4810/4800 systems I/O assemblies for CompactPCI support a total of four slots each.
The Sun Fire 6800/4810/4800 systems are designed to be repaired and upgraded easier and faster than previous systems. This is due to the placement of active ASICs mounted on the Repeater boards. With two Repeater boards installed in the system, an alternate path is available through the second board, if one board fails. The Sun Fire 3800 system is the only system that comes with all of the active components of the Repeater board built onto the centerplane.
The Repeater boards provide two functions: redundancy for reliability, and a higher bandwidth. The system can operate with only one Repeater board. The Repeater board acts as a switch and connects multiple CPU/Memory and I/O boards together. The three components are the Address Repeater (AR), the Sun Fire system data controller (SDC), and the data crossbar (DX).
In standard operation, the Sun Fire 6800 system has four Repeater boards which are used to route ten buses (six CPU and four I/O). If one of the Repeater boards fail, the system can continue to operate in a degraded mode with one pair of adjacent Repeater boards. The data width is cut in half and the two Repeater boards will route the ten buses.
Because the Sun Fire 4810 and 4800 systems support only two Repeater boards, the two Repeater boards operate together to route five buses (three CPU and two I/O). If one of the Repeater boards fail, the data width is cut in half and one Repeater board can route the five buses.
The System Controller board contains the system clock and a service processor. One System Controller board is required per system. You can install one additional System Controller board for redundancy in all the Sun Fire systemsystems. The Sun Fire 6800 system comes standard with two System Controller boards installed at the factory. The processor on the board is a microSPARC IIep with its own POST/OBP flash PROM and 8 Mbytes of DRAM. The processor also has a 33-MHz PCI bus with two devices on it.
With two System Controller boards in each system, if one System Controller board fails, the other System Controller board can take control of the system without causing a disruption in the main system operation. The System Controller board has a 10/100-BASE-T Ethernet connection and an Ebus interface for a variety of devices. These include a TOD/NVRAM device, flash PROM for extra NVRAM space, a large (4 Mbyte) flash PROM to hold the OS code, and one 16552 dual serial port device.
The System Controller board performs the following main functions:
The system controller provides five ports: domain A console, domain B console, domain C console, domain D console, and the system controller shell. The system controller shell provides the following:
The system controller software sequences the booting of the system by:
The system controller software provides tools for changing the configuration of the system, and it also logs errors.
For more information on the system controller, refer to the Sun Fire Midrange Systems Controller Command Reference Manual.
When two System Controller boards are installed in Sun Fire 6800/4810/4800/3800 systems, the second board is a redundant System Controller board. Each System Controller board can check the health and status of the other System Controller board. If the main System Controller board (SC0) fails, the redundant System Controller board (SC1) takes over operations without causing a disruption of the system operation.
The system controller provides a virtual key switch for each domain. The key switch command controls the position of the virtual key switch for each domain.
The system controller provides a Solaris software console for each domain. The Ethernet or serial port of the System Controller board is the physical connection for the Solaris software console. The serial port can support only one console at a time. However, the Ethernet port can support many consoles simultaneously. The system controller multiplexes these physical connections to provide console services for each domain and for the system controller.
The Sun Fire system TOD/NVRAM chip is located on the System Controller board. The system controller multiplexes the physical TOD chip to provide TOD services for each domain and for the System Controller board. The system controller also provides for synchronizing the TOD between the main System Controller board and the redundant System Controller board.
The Sun Fire systemsystem has a large number of sensors that monitor temperature, voltage, and current. The system controller polls these devices periodically. If thresholds are exceeded, the system controller shuts down various components to prevent damage.