You can connect 2 motherboards together, but it's not worth the investment. 4 or 2 CPU cores are enough for modern usage, which you can easily get in a mid-range CPU these days.
If both motherboards have Ethernet, you can connect them using a crossover cable. If they still have a serial port, you can use an empty modem cable. If they have FireWire, you can use it to connect to the network. More info to visit this site.
















