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Sustaining Moore's Law - 10 Years of the CPU

Sustaining Moore's Law - 10 Years of the CPU



Moore's Law

Moore's Law

In early 1998, Intel released its low-end budget processor, the Celeron, which was then based on the Pentium II. It ran at a mere 266MHz and was manufactured on a 250nm process. When Intel introduced its latest iteration of the Celeron brand ten years later in January 2008, the Celeron had two processing cores, ran at 2.0GHz and was built on a 65nm process.

As anyone involved in the field of computing will tell you, Moore's Law is probably one of, if not the definitive statement of the industry. Ever since Intel's co-founder, Gordon E. Moore noted in 1965 that the number of transistors placed on an integrated circuit doubles roughly every two years, this has remained more or less true. Implicit in this observation is that computing power grows exponentially and even as we entered the 21st century, futurists have predicted that this trend will continue for some years to come.

While Moore's Law has since been expanded to include the exponential growth of all aspects of computing hardware, the original statement referred specifically to the semiconductor industry. Hence we felt that it was very appropriate to cite this as we look back on the CPU developments of the past decade.

So far, computer scientists and engineers have succeeded at maintaining this remarkable trend. We'll be highlighting some of the significant milestones during this period in more detail later and you can see for yourself the fruits of their labor. Since the scope for processors can be extremely broad, we are limiting our discussion to the x86 platform and its main players, with the occasional digression.

In our opinion, the last ten years of the CPU industry can be summarized in a single sentence:

"The race for clock speeds i.e. the Megahertz/Gigahertz race has evolved into one between multiprocessors."

In 1998, Intel's flagship Pentium II processor was running at a maximum clock speed of 450MHz. This would be supplanted within a year by the Pentium III, which despite the new name, did not differ that much from its predecessor. It even started at the same 450MHz clock as the Pentium II. However, the Pentium III had Intel's first implementation of SSE (Streaming SIMD Extensions) instructions, which reduced the number of instructions needed for each data set, thereby improving the efficiency of the operation. With new registers and floating point support, the SSE instruction set has been widely adopted by both AMD and Intel for their microprocessors and the current iteration is SSE5, introduced by AMD in 2007.

That same year in 1999 would also see the debut of AMD's K7, known as the Athlon, which would become the company's most successful CPU. Featuring a next generation x86 micro-architecture, the Athlon would seriously challenge Intel's dominance of the x86 market. Among other notable technological feats found in the Athlon was a new triple-issue floating point unit (FPU) that turned AMD's traditional FPU weakness into a strength, such that enthusiasts would be talking about AMD's FPU performance lead for years to come.

While the K7 heralded the beginning of an era where the incumbent market leader Intel faced serious competition for the first time in a long while, the company continued to ramp up the megahertz with further iterations of the Pentium III, with the 180nm Coppermine Pentium III that ran up to a maximum of 733MHz. Unfortunately, production woes plagued the transition to 180nm and despite the fact that the new Coppermine processors were significantly faster than the original Pentium III thanks to its full-speed 256KB L2 cache, the Athlon proved to be very compelling, particular in terms of pricing.