Say I can get some used MB with CPU and RAM on it at a very low price, and a DMA 33 hard drive, home made powersource, how am I gonna get all thoese MB connected? Using PCI slots? AGP slots? Or para. Ports? USB ports? Does Beowulf even support HD farm? That would be mind-blowing advance, for old hardwares, that is. This is my premature understanding: First, you need a master computer, giving orders through a main bus or something like that to other slave computers, the master computer will allocate the computing task to each of them, then wait and collect the results, PCI should be used to connect each computer, because most boards have more than 1 PCI slots, and the addressing and interrupt is much easier as most ppl use it so the technology relevant should be rather mature. Only the master computer will have a harddrive, hosting the Beowulf system. I could be wrong, though, and most likely I'm wrong.