IBM and the Georgia Institute of Technology announced that their researchers have demonstrated the first silicon-based chip capable of operating at frequencies above 500 GHz — 500 billion cycles per second — by cryogenically “freezing” the chip to 451 degrees below zero Fahrenheit (4.5 Kelvins). Such extremely cold temperatures are found naturally only in outer space, but can be artificially achieved on Earth using ultra-cold materials such as liquid helium. (Absolute Zero, the coldest possible temperature in nature, occurs at minus 459.67 degrees Fahrenheit).
By comparison, 500 GHz is more than 250 times faster than today’s cell phones, which typically operate at approximately 2 GHz. Computer simulations suggest that the silicon-germanium (SiGe) technology used in the chip could ultimately support even higher (near-TeraHertz – 1,000 GHz) operational frequencies even at room temperature. There’s a couple of video’s here and here.