> speed in the, then, current serial circuitry. If you could get faster, > and accurate electronics, which you *now* can, serial can manage faster > rates, easier and more reliably. No. The reason is quite different. When you have a parallel cable all the wires are never quite the same length, diameter or metal properties (ditto tracks on a board). That means that the signals arrive at the ends of each wire at different times. Your clock rate is thus limited by the cable quality and length as well as these propogation delays. That is what limits PATA to UDMA/133. Any faster and the bits just won't turn up on time. If you have one or more serial links with their own clock the clock arrives with the data on that link as it does for example with ethernet. Alan
