"Now, researchers at Cornell University have created a silicon
microresonator that vibrates at 4.51 gigahertz, the highest frequency
ever recorded in such a silicon device. Other researchers have
demonstrated silicon microresonators that vibrate up to 1.5 gigahertz,
say the Cornell researchers."
4.51 GHz clock
Men her er vi vel udenfor hvad der kan gavne digital audio, skulle man tro.