The motherboard is a printed circuit board that contains most of the active electronic components of the PC node and their interconnection. The motherboard provides the logical and physical infrastructure for integrating the subsystems of the Beowulf PC node and determines the set of components that may be used. The motherboard defines the functionality of the node, the range of performance that can be exploited, the maximum capacities of its storage, and the number of subsystems that can be interconnected. With the exception of the microprocessor itself, the selection of the motherboard is the most important decision in determining the qualities of the PC node to be used as the building block of the Beowulf-class system. It is certainly the single most obvious piece of the Beowulf-node other than the case or packaging in which it is enclosed.
While the motherboard may not be the most interesting aspect of a computer, it is, in fact, a critical component. Assembling a Beowulf node primarily involves the insertion of modules into their respective interface sockets, plugging power and signal cables into their ports, and placing configuration jumpers across the designated posts. The troubleshooting of non-functioning systems begins with verification of these same elements associated with the motherboard.
The purpose of the motherboard is to integrate all of the electronics of the node in a robust and configurable package. Sockets and connectors on the motherboard include the following:
Microprocessor(s)
Memory
Peripheral controllers on the PCI bus
Peripheral controllers on the EISA bus
Floppy disk cables
EIDE cables for hard disk and CD-ROM
Power
Front panel LEDs, speakers, switches, etc.
External I/O for mouse, keyboard, joystick, serial line, etc.
Other chips on the motherboard provide:
The system bus that links the processor(s) to memory
The interface between the peripheral buses and the system bus
Programmable read-only memory (PROM) containing the BIOS software
Microprocessor(s)