Scientists unveiled <A HREF="http://news.yahoo.com/s/ap/20080609/ap_on_hi_te/fastest_computer">the world's fastest supercomputer,</A> a $100 million machine that for the first time has performed 1,000 trillion calculations per second in a sustained exercise.

The technology breakthrough was accomplished by engineers from the Los Alamos National Laboratory and IBM on a computer to be used primarily on nuclear weapons work, including simulating nuclear explosions.

The computer, named Roadrunner, is twice as fast as IBM's Blue Gene system at Lawrence Livermore National Laboratory, which itself is three times faster than any of the world's other supercomputers, according to IBM.