System Board Sets
DIGITAL Server 9100 Series User's Guide
1-15
Processor Boards
The system must include a minimum of two and up to four processor boards (two per system board)
capable of supporting up to eight Pentium Pro processors (two per processor board). Each processor board
has two processor sockets. The board contains termination circuitry required by the GTL+ signaling
environment, DC to DC converters for power to each processor and termination circuitry, and logic for
I
2
C support and clock ratio programming.
The primary system board has two connectors for processor boards: CPU 1 and CPU 2. Processor boards
must be filled on the primary system board first. The secondary system board also has two connectors:
CPU 3 and CPU 4. Each connector has subtle differences in pinout. Either a processor board or a bus
termination board must be plugged into each processor board connector.
Processors
The server supports the following types of processors:
•
Single 200 MHz Pentium Pro with integrated 512 KB write-back cache
•
Dual 200 MHz Pentium Pro with integrated 512 KB write-back cache
•
Single 200 MHz Pentium Pro with integrated 1 MB cache
•
Dual 200 MHz Pentium Pro with integrated 1 MB cache
On the secondary system board, you can upgrade with a single processor per board to two processors per
board with a processor upgrade kit. Four processors are required on the primary system board.
Processor activity is indicated by LEDs on each system board. Flashing red LEDs indicate normal
processor activity. If lit solid or if the LED light is off, the processor may have failed. Refer to the
previous sections on board connectors and component locations to determine the location of processor
LEDs on the system boards.
Bus Termination Board
Either a bus termination board or a processor board must be plugged into each processor board connector.
The termination board provides GTL+ (Gunning Transceiver Logic) signal termination and voltage
regulation.
