IBM researchers have pushed a silicon-based microprocessor to speeds of 500 gigahertz, more than 250 times faster than a typical commercial chip in a cell phone.

The research shows that chip makers can reach high speeds with low-cost manufacturing techniques and commercial silicon-based chip technology, said John D. Cressler, a professor at Georgia Tech's School of Electrical and Computer Engineering.

The new research, announced Tuesday by IBM, could also lead to more efficient chips, opening up new markets. Running at extremely high speeds, these chips could now find new applications in commercial communications systems, defence electronics, space exploration and remote sensing, according to IBM.

A team of scientists from IBM and Georgia Tech used an old hacker's technique to avoid melting the chip at such high speeds.

Extreme video gamers chill their chips with refrigerated mineral oil stored in the garage, but this team was able to make the chip much colder.

First, the researchers built a prototype silicon-germanium (SiGe) chip that ran at 350GHz at room temperature. IBM, in Armonk, New York, has been mixing germanium with silicon since 1998, using the mixture to make chips for cell phones and other mobile devices that demand reduced power consumption.

Then they used liquid helium to freeze their microprocessor to 451 degrees below zero Fahrenheit. Nature's coldest temperature, known as absolute zero, is just a few degrees lower, at minus 459.67 degrees Fahrenheit. With no risk of melting the chip, they pushed it to 500GHz.

By contrast, the latest commercial dual-core server chips from Intel and AMD run at speeds between 2.5GHz to 3.5GHz.

The researchers now plan to return to their lab and find a way to push the chip even faster. IBM's computer simulations show that their chip could reach speeds of 1,000GHz, known as 1 Terahertz.