Sun Microsystems is trying to do for computing what all the king’s horses and men failed to do for Humpty Dumpty. For decades, the semiconductor industry has broken silicon wafers into smaller chips to improve manufacturing yields.

Now Sun has found a way to reconnect the chips so they can communicate with each other at such high speeds that computer designers can build a new generation of computers that are faster, more energy-efficient and more compact.

The computer maker, which is based in Santa Clara, California, plans to announce on Monday that it has received a $44 million contract from the Pentagon to explore the high-risk idea of replacing the wires between computer chips with laser beams.

The technology, part of a field of computer science known as silicon photonics, would eradicate the most daunting bottleneck facing today’s supercomputer designers: moving information rapidly to solve problems that require hundreds or thousands of processors.

Processor and memory chips are currently made by etching hundreds or thousands of identical circuits onto a single wafer of silicon and then slicing that wafer into fingernail-size chips. That manufacturing process ensures that if there is a defect at a single spot on the giant wafer it will not ruin the entire batch of chips.

The drawback in the approach is that wires have to connect the chips in a computer. This causes a fundamental limit in processing power because data moves between chips at lower speeds, creating significant bottlenecks.

The wires that connect chips are analogous to the on and off ramps that cars use to move between freeways — just as cars slow down as they move onto city streets from multilane highways, electrical signals run more slowly between chips. The bottlenecks also generate additional electrical current and heat.

... contd.