By Tikkler - October 9, 2000

Infobox

Product Reviewed: Pentium III 1GHz (1000MHz) Product Page Manufacturer: Intel Home Page Suggested Retail Price*: Unspecified - About $700 USD * As of the time of this writing

[Ed: Many readers have expressed that there are some factual errors in my information regarding the Pentium Pro processor. I have included some of their points that they have brought up to me throughout the entire review.]

"You can't teach an old dog new tricks"--say that to Intel, and they'll prove you wrong.

1997--Intel brought the world their new P6 core in the form of the Pentium Pro and, later, the Pentium II. Before the ages of the P6 core, namely, the P5 core used in the original Pentium processor, the L2 cache, which is basically a small amount of very fast memory used to store data that the processor predicts it will need next, was built onto the motherboard itself. Of course, back in those days, the high-end bus speed was 66MHz, and, by having the L2 cache on the motherboard, it meant that this fast storage area would be limited to a maximum of 66MHz. Having this slow L2 cache on the motherboard meant that it hampered, considerably, the performance of the 200MHz+ processors that we were beginning to see in those days.

Then came the Pentium Pro processor, which was the first-ever processor that Intel released based on their new P6 core. This new P6 core, along with a .32-micron process, allowed Intel to place the L2 cache right on the processor core itself and allowing it to run at the same speed as the processor. This full-speed L2 cache allowed the Pentium Pro to run significantly faster in a lot of applications than its Pentium siblings at the same speed.

[Ed: Correction - The L2 cache was placed in the package itself in the form of cache modules that were made on a .50-micron process and not directly on the die. Also, the core of the Pentium Pro's were manufacturered on .50-micron or .35-micron processes.]

Unfortunately, having the full-speed L2 cache on the processor meant increased costs in manufacturing, meaning increased costs for the consumer, and more complex processor designs that the .50-micron and .35-micron processes just couldn't handle very well--Intel found that they could only push the speed of these Pentium Pro processor to a maximum of 200MHz.

To simplify things, yet still maintain almost the same level of performance as the Pentium Pro processor allowed, Intel introduced the Pentium II processor. This processor also used a similar P6 core (but this time, built on the newer .25-micron processor) that the Pentium Pro did, except without the L2 cache right on the core itself. Intel decided to place 512KB of L2 cache beside the core itself and running that at half the speed of the core. This, as expected, allowed Intel to drive up the speed of the processors that it was able to produce and lower the overall prices of their processors because they could produce more processors in every batch that they made.

Of course, placing the L2 cache right beside the processor itself meant that Intel had to make a new packaging format. Before the Pentium II, all processors were packaged in a socket form with only the core on the packaging, but with the advent of the Pentium II, there needed to be room to place the L2 cache right beside the core, hence, the Slot 1 packaging. Basically, Intel placed the core and the L2 cache all onto a rectangular piece of PCB, which was then plugged into the motherboard.

Intel has stuck with this P6 + half-speed L2 cache combo along with the Slot 1 packaging for quite some time. They've taken this setup through many stages: first came the first generation Pentium II's with the 66MHz FSB, then the 2nd generation Pentium II's with a 100MHz FSB and onto the controversial first generation Pentium III, which was basically the same thing as a Pentium II, except at higher frequency speeds, a set of new SIMD instruction sets that only worked on applications and games that supported them and a controversial processor ID number.

It was until some point in the summer of last year, when AMD was about to release their 7th generation Athlon processor, that Intel decided they needed to get up and make a change to this aging combo.

[Ed: Correction - Intel was, in fact, already manufacturing processors with on-die, full speed L2 cache in the form of the Celeron processor. An early sign of threat coming from AMD's Athlon prompted Intel's decision to set their goal of bringing full-speed L2 cache to their Pentium III line of processors in motion.]

On to: The New Pentium III