The processor space race largely comes as a function of Moore's Law. Under Moore's Law, the number of transistors on a chip doubles roughly every 18 to 24 months through, among other factors, shrinking the transistors. The transistor explosion has allowed computers to experience continual improvements in performance. But smaller, faster transistors in greater numbers mean that chips need more electricity, which creates a host of problems. Synchronising ever faster pulses across more complex circuits makes huge demands on design skills. At the same time, faster signals in greater numbers can lead to signal interference. In addition, more energy means more heat. Without any structural changes, for instance, future power-hungry chips will be hotter than an equivalent slice of the sun's surface. "Physics was once our friend," said Nathan Brookwood, an analyst at Insight 64. "Now it is our enemy." With Double Gate, IBM is fiddling with the basic structural elements of transistors. Transistors generally consist of three basic elements: a source, a gate and a drain. The gate normally sits on top of the connection between source and drain, much like a thumb on top of a hosepipe. Changing the voltage on the gate changes the resistance between source and drain, in effect pressing down or letting up on the hosepipe. This can be used to change logic states in circuits between zero and one -- the true and false at the heart of computing. In Double Gate transistors, the gate, rather than merely sitting on top of the source and drain, wraps around the source-drain connection like a clamp -- the same voltage thus exerts greater change, resulting in a more efficient system. IBM is also using silicon-on-insulator (SOI) in this architecture, which introduces a thin layer of insulating material to the side of the transistor, keeping charge effects in the substrate of the chip well away from the active, switching area. SOI is one of the crucial elements of the new design, Davari said. A form of SOI is also critical to Intel's upcoming "Terahertz" transistor, which Davari finds ironic because Intel has criticised it for years. "They've been bashing it at all the technical conferences," Davari said. IBM has promoted SOI since 1998 and incorporated the technology in several chips. Although Intel executives admit that the company has criticised SOI, researchers there claim that their version of SOI, due out toward 2005, is better. IBM will use Double Gate transistors in its own chips and license it to its foundry clients, Davari said. ZDNet UK's Rupert Goodwins contributed to this report. See Chips Central for the latest headlines on processors and semiconductors. To find out more about the computers and hardware that these chips are being used in, see ZDNET UK's Hardware News Section. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the Chips Central forum Let the Chips Central editor know what you think by email. And read other letters.





