IBM has taken a large stride in its race with Intel to make faster, smaller chips by building silicon transistors from a rare combination of metals.

Both companies announced in January that they had discovered the special materials they needed to build "high-k metal gate" transistors. The special materials are much better insulators than standard silicon dioxide, a crucial trait as chip designers struggle to fit more and more transistors on each microprocessor, since electricity tends to leak from the closely-packed wires, making them hot and inefficient.

Until now, neither company had announced the ingredients of this new mix of materials. But IBM researchers said yesterday that they had used their Blue Gene supercomputer to model 50 combinations of hafnium dioxide and basic silicon. The company plans to build chips based on the new mixture in 2008.

The new material looked good in theory, but IBM engineers had to create simulations of different mixtures to avoid any surprises when they added it to semiconductor production lines, said Alessandro Curioni, a supercomputing expert at IBM's Zurich Research Laboratory. Curioni was one of three authors who published this research in a paper published in the January edition of the scientific journal Physical Review Letters.

The team used new algorithms and a Blue Gene/L supercomputer with 4,096 processors to crunch the numbers. The program took about five days to run a simulation for each combination of ingredients, modelling the interaction between individual particles for the 600 atoms in every model. If the researchers had used a typical notebook PC, the 250-day job would have taken them 700 years, he said.

Despite IBM's advance, Intel insists it is on track to reach markets first with chips using its own type of "high-k metal gate" transistors. Intel plans to use the technology in a family of 45-nanometer architecture chips scheduled for launch later in 2007, the company said.