Research in operating systems has shown that most of the time in the computer is spent with I/O operations, like disk write/read, network I/O, etc., while the processors' speeds have advanced so much that they mainly stay idle. Even CPU intensive operations, like compiling and long calculations are done relatively quickly. So why would we need much faster CPUs, let's say a CPU of some THz clock rate? The effect would have been almost ignorable, knowing that most of the time would be spent with peripherals. Don't we have to improve all the hardware in parallel before we think of major advances in CPU speeds? Why for example would one have to buy the expensive 3GHz+ processors while a much cheaper 2GHz processor would suffice?