Intel has confirmed plans for its desktop processors before the multi-core era arrives - and they include scrapping a 4GHz version of its flagship Pentium 4 product. The company has decided instead to "realign its engineers around the company's new design priorities".

The past year has been marked by huge shifts in Intel's design and marketing philosophies. After years of promoting clock speed as the most important indicator of processor performance, it now believes that introducing multi-core products and new silicon features, collectively known as the "Ts", are the best ways to improve processor performance.

The company has made the tough decision to break Intel COO Paul Otellini's promise to release a 4GHz Pentium 4 product, and will move engineers working on it to other projects.

Earlier this year, Intel delayed the arrival of the 4GHz Pentium 4 until the first quarter of 2005. At a financial analyst meeting in November of 2003, Otellini promised to have that product out by the end of 2004, but much has changed at Intel since that meeting.

In the meantime, Intel confirmed it will introduce a faster front-side bus in its Pentium 4 Extreme Edition chips, which will top out at 3.73GHz, as expected. Starting next year, the company will add an additional 1MB of cache memory to its Pentium 4 chips based on the Prescott 90 nanometer core, and cap the clock speed of that product at 3.8GHz.

Intel has re-evaluated many product decisions this year after CEO Craig Barrett wrote a memo chastising the company for its string of product delays and manufacturing glitches. The memo called for Intel to focus on products that can be delivered on time and without incident, and the decision to forgo the 4GHz chip seems linked to that.

It's simply easier to increase performance by adding cache memory to a processor, said Bill Kirby, director of platform marketing at Intel. Cache memory stores frequently accessed data close to the processor where it can be retrieved more quickly than data stored in the main memory.

Industry-wide concerns about the amount of power required to keep highly clocked processors running has caused most chip companies to move away from high-clock-speed designs. It is now focusing on the "platformisation" of its chips, a concept that Otellini touched on during his keynote address at the Fall Intel Developer Forum last month.

There are no technical or thermal limitations to prevent Intel from releasing a 4GHz product, Kirby said. But there were practical limitations, so that to release such a product Intel would have to devote time and energy to tweaking circuit designs and testing those chips, he said.

"Performance still matters, and performance on multiple vectors still matters," Kirby said. "The fundamental decision was whether to chase megahertz ... or to bring in other features like cache and multi-core."

Those additional vectors include features such as hyperthreading, the software-based technology that Intel has used in its Pentium 4 chips for more than a year to fool a PC's operating system into believing the PC has two processors.

During its usual second-quarter chipset introduction in 2005, Intel will introduce the other platform technologies it has spoken about during the last several IDFs, Kirby said. These include: VT, or Vanderpool Technology, a virtualisation feature; LT, or LaGrande Technology, hardware-based security features; EM64T, Intel's name for its 64-bit extensions to the x86 instruction set, and AMT, or Active Management Technology, a new feature aimed at making PCs easier to manage.

After that chipset launch, Intel will be ready to introduce its first dual-core desktop chips. Those chips will keep the Netburst architecture in at least the first generation of dual-core products, and probably into the second, Kirby said.

He declined to offer further details about Intel's dual-core desktop chips, but Intel's customers will receive details on the new chips over the next week or so, Kirby said.