IBM and Georgia Tech have <A HREF="http://news.zdnet.com/2100-9584_22-6085568.html?tag=nl.e589">coaxed a chip to run at 500GHz,</A> a record for a silicon-based device, by dropping the temperature to minus 451 degrees Fahrenheit. The experiment is part of a project to explore the ultimate speed limits of silicon-germanium (SiGe) chips. SiGe chips are similar to standard silicon chips, but they also contain germanium for better performance and lower power consumption.