Intel has always been pushing the clock speed (GHz) of chips, and most retailers use this as a selling point. However, Intel no longer sees this as the value point of a CPU. Instead, Intel wishes to reflect on the CPU as a whole, not just a speed, and has shifted towards a new naming structure.

This new naming scheme has currently separated the mobile and desktop processors, excluding the Extreme Edition line, into 3 segments; the 3XX, 5XX, and 7XX series. Although most will relate it to the BMW line of motor vehicles, the 3, 5, and 7 are the most commonly used numbers for various product lines among manufacturers.

Why has Intel made this shift?

"Intel's use of processor numbers is meant to allow consumers to quickly differentiate among comparable processors and to analyze or take into account more than one processor feature during the selection process.

"Intel's processor numbers will comprehend the following key features: underlying architecture, cache, front side bus, and other Intel technologies, in addition to clock speed. Over time, these processor numbers will allow end customers to intelligently and accurately distinguish among individual processors by taking into account a broader set of features that contribute to the overall user experience."

Many have heard of cases where customers walk into a store to purchase a computer. They encounter two systems, a $600 system with a 2.8GHz processor, and a $1200 system with a 2.4GHz processor. Subtracting out any excess add-ons and looking at the base cost of the system, the slower system (2.4GHz) still costs more? That doesn't seem right, so the customer feels that the 2.8GHz must be the "new" product being pushed, and it's faster!

Well, what it turns out to be is that the 2.8GHz CPU was an Intel Celeron processor, while the 2.4GHz CPU was an Intel Pentium 4 Processor with Hyper-Threading Technology. Needless to say, the 1MB L2 cache, 800MHz front-side bus, and the enhanced feature set of the Pentium 4 will outperform the "faster" Intel Celeron processor.

This story, although made up, is not uncommon. Especially in today's society where most decision makers may not have the technical knowledge to understand why a slower clock speed would be faster than the obviously faster processor.

Intel's processor number naming scheme will help alleviate problems such as this. Consumers will know that a 2.8GHz processor in the 3xx series is not the same as the slower rated 2.4GHz in the 5xx series.

The processor numbers are "meaningless" - by themselves, they have no meaning. Without a guide, or detailed list, it would be difficult to tell what a 530 processor is and what a 540 is, and you can't compare between series, comparing a 7xx series to a 5xx series assuming the 7xx is better since it is a bigger number would not be valid. Intel has selected numbers which have been used already, and are known to be effective.

Since Intel is no longer using the CPU clock speed as the performance indicator, it is likewise not being used to differentiate within the processor number scheme. Instead, processor number variations will let us know that one or more of the following core CPU items are being affected:
CPU architecture, or the basic design of a microprocessor (may include process technology and/or other architectural enhancements).
Cache, or the temporary storage area for frequently accessed or recently accessed data (having certain data stored in a cache speeds up the operation of the computer. Cache size is measured in megabytes (MB) or kilobytes (KB)).
Clock speed (GHz/MHz), or the speed of the processor's internal clock, which dictates how fast the processor can process data (clock speed is currently measured in GHz (gigahertz, or billions of pulses per second)).
Front Side Bus, or the speed of the connecting path between the processor and other key components such as the memory controller hub (measured in gigahertz, GHz, and megahertz, MHz).

"A higher number within a processor family can indicate more processor features, more of a specific processor feature, or a change in architecture. Note that in some cases, a higher number processor may potentially have more of one feature and less of another.

"For example, there may be a case where the processor number increments due to a front side bus increase (e.g. from 400 MHz to 533 MHz), or cache increase (e.g. from 512KB to 1MB), even though the clock speed may stay constant or decrease. When comparing processor numbers, it's important to keep in mind that there are other key features outside of clock speed that contribute to the overall value of the processor."

A change in processor number may not mean a change in speed, or better performance. Intel is trying to make this fact well known.

The following is a simple list showing processors under the new naming system, and what they are.

Intel Pentium 4 processors 550, 540, 530, 520 supporting Hyper-Threading Technology
550 = 3.40 GHz, 1MB L2 cache, 800 MHz front side bus
540 = 3.20 GHz, 1MB L2 cache, 800 MHz front side bus
530 = 3.00 GHz, 1MB L2 cache, 800 MHz front side bus
520 = 2.80 GHz, 1MB L2 cache, 800 MHz front side bus

Intel Celeron D processors 335, 330, 325
335 = 2.80 GHz, 256k L2 cache, 533 MHz front side bus
330 = 2.66 GHz, 256k L2 cache, 533 MHz front side bus
325 = 2.53 GHz, 256k L2 cache, 533 MHz front side bus

Intel Pentium M processors 755, 745, 735
755 = 2.0 GHz, 2MB L2 cache, 400 MHz front side bus
745 = 1.8 GHz, 2MB L2 cache, 400 MHz front side bus
735 = 1.5 GHz, 2MB L2 cache, 400 MHz front side bus

Mobile Intel Pentium 4 processors 532, 518 supporting Hyper-Threading technology
532 = 3.06 GHz, 1MB L2 cache, 533 MHZ front side bus
518 = 2.80 GHz, 1MB L2 cache, 533 MHZ front side bus

Intel Celeron M Processors 330, 320
330 = 1.40 GHz, 512k L2 cache, 400MHz front side bus
320 = 1.30 GHz, 512k L2 cache, 400MHz front side bus

At the moment, higher numbers do equate to better performance, but that is subject to change, and most likely will this summer, when Intel's newest Pentium 4 lines hit the market.