Semiconductor vendor AMD is developing a new kind of processor designed to run at high speeds without the need for a cooling fan.

The new chip uses a form of pure silicon, a natural substance that dissipates heat build-up more effectively than existing materials. This process is currently being tested on a prototype next-generation AMD Athlon chip, codenamed Palomino, which runs at 1.5Ghz without external cooling.

Exact details of the temperatures at which the chips will run have yet to be announced. US-based Isonics, which manufactures the isotopically pure silicon, is working with AMD on the project.

The expense of the new material is said to increase the manufacturing cost of bulk wafers by about $10 per chip. However, fans costing between $10 and $30 would no longer be needed, and would also reduce the noise levels of a PC.

Meanwhile, abnormally high noise levels in AMD's current 760-based Duron motherboards has caused a number of distributors to delay shipping. AMD representatives declined to give details of what causes the additional noise, but stressed that it was a minor problem.

The chipset was officially released in October. However, shipment delays, even before this latest setback, have resulted in many distributors revealing that they do not expect bulk supplies to be available until January 2001.