Intel has acknowledged that it hit a “thermal wall” on its microprocessor line by raising the clock speed of its chips and reducing the minimum feature size to 90 nanometers from the industry standard of 130 nanometers.

“Classical scaling is dead,” said Bernard S. Meyerson, chief technologist for I.B.M.’s systems and technology group. “In the past, the way everyone made chips faster was to simply shrink them.”

Today, however, transistors have shrunk so radically that in the most crucial places they are no more than five or six layers of atoms thick. As a result, they have become increasingly porous, permitting electric current — and heat — to cascade out even when they are switched off.

As a result, Intel is changing its product strategy, announcing it would abandon two advanced chip development projects, code-named Tejas and Jayhawk, and obtain more computing power by a “dual core” processor structure rather than increasing the speed of a single processor.