High-speed circuit also saves power

A new high-speed computer circuit from IBM is leaving the closest competitors in the dust. The new circuit has tested at speeds almost five times faster than other top-speed chips.

The circuit employs a design known as the

interlocked pipelined complementary metal oxide semiconductor


Stanley Schuster, a research staff member at IBM, stressed the product is not a microprocessor.

“In think it has to be understood that what we built is really a cross-section of part of a multiplier,” he noted. “So, yes we’ve achieved that the part we’re running is as fast as 4.5GHz, but that is not an entire microprocessor.”

The key to the IPCMOS design is a distributed clock function. Where there would normally be one synchronous clock that’s distributed throughout the entire chip, IBM’s design uses locally generated clocks, Schuster said.

“What we’ve done is built an asynchronous, interlocked, hand shaking circuit technique that generates the clocks locally when there is an operation to be performed,” he said.

Peter Cook, a fellow IBM researcher and manager of the high-performance system group at the Thomas J. Watson Research Center in York Town Heights, N.Y., added it is a real challenge to distribute a global synchronous chip to all the parts of a chip.

“As you start speaking of gigahertz and beyond clock frequencies, you have a total of a nanosecond or less to get that clock to all of the parts of the chip that it has to go to. And that could be hundreds of latches and thousands of bits. So generating that clock is an exceedingly difficult problem,” Cook said. “By making only a local clock, we actually have a simpler problem and that’s part of what allows the circuitry to run as fast as it does.”

Schuster was excited by the power-saving applications this chip could have. He said that the local clocks are enabled only when there is an operation to be performed, compared to a synchronous system where the clock is running continuously.

Schuster explained that the predictions in the next several years are for processors to have 150 to 160 watts of power, stating that in addition to the distribution of the products, the power that existing chips are consuming has gone up dramatically.

“We see factors of two or more reduction in power with these techniques. The power reduction may be as important or more important than the speed, although the speed obviously is important too,” he said.

Cook joked that the battery on a laptop or ThinkPad may last for an entire flight soon.

Linley Gwennap, principal analyst for Mountain View, Calif.-based Linley Group, agreed that one of the key issues was the reduction in power.