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The processor of a computer is the ‘brain’ of the system.  Basically, whenever anything occurs within the computer, it’s almost guaranteed processor will be involved.  Because of the way AMD has begun to label there processors, sometimes MHz and PR ratings can become myths. 

  • Note: A higher MHz doesn’t necessarily mean higher performance. This is what I like to think of as the “AMD” theory.

Because AMD’s processors are more efficient at performing functions as compared with an Intel processor, an AMD processor will perform as well as or better than an Intel processor at a lower MHz.

There are different types of AMD processors (Duron, Athlon, Athlon XP, Athlon MP, Athlon XP Barton, and the upcoming Opteron / Athlon 64) and each processor has a different performance level.  At the same clock speeds, a Duron would perform worse than an Athlon and an Athlon would perform worse than an Athlon XP, and the Athlon XP would perform more slowly than an Athlon XP Barton.  The Athlon MP processor is the exact same thing as an Athlon or Athlon XP, but is able to be used in systems with more than one processor.  Because the Opteron and Athlon 64 processors haven’t made it to the consumer side of the market, they won’t be discussed in this article. (But if you’re interested in taking a peek at their performance, look here.)

Building an AMD Based Computer System - Systems 20

AMD’s latest offering, the Opteron, has caught the attention of the enterprise, small business and super computing sectors with its support for both 32-bit and 64-bit applications.

AMD uses PR ratings which were derived from the performance of the AMD Athlon Thunderbird processor.  Basically, an Athlon XP 2000+ will perform the same if an Athlon Thunderbird were able to theoretically scale to 2000MHz (2GHz).

What makes the Athlon XP Barton processors different from the normal Athlon XP?  The main difference in the processors is the amount of level 2 (L2) cache onboard the chips.  The normal Athlon XP has 256Kb of L2 cache while the Athlon XP Barton ramps that up to 512Kb. What does that mean? Well, basically the processor is able to hold more information at its fingertips and doesn’t have to rely upon RAM as much.  This results in a performance increase in many scenarios.  The Athlon XP Barton (from now on known as the AXP-B) processors currently come in four flavors.  The AXP-B 2500+ is the lowest clocked Barton and is clocked at 1.83GHz.  The AXP-B 2800+ is clocked at 2.08GHz and the 3000+ is clocked at 2.16GHz.  The AXP-B 3200+ is clocked at 2.2GHz and uses a different front side bus from the other AXP-Bs, which we’ll discuss next.

The front side bus (FSB) speed of a processor becomes important whenever you begin to talk about gaming and distributed computing.  AMD processors currently come in three flavors of FSB: 133MHz, 166MHz, and 200MHz.  Now, you’ll see “266MHz, 333MHz, and 400MHz” quite a bit out there, but these numbers are only generated because the true FSB is doubled.  Because this becomes quite technical, we’ll leave it to another article but I will note that if you buy a higher FSB processor you’ll have a couple of tradeoffs: You’ll have better overall performance, but you will have to buy faster (read: more expensive) RAM to support it.  Also, your motherboard must support the FSB of the processor you choose.

There are several questions that are frequently asked about processors:

  • What kind of processor do I need?
  • How fast should I get?
  • What front side bus processor should I use?
  • What do dual processors do for performance?
  • Will a stock heatsink provide adequate cooling?
  • Should I overclock?

Selecting a Processor

If this system you are building is going to be for your grandma doing web surfing and sending pictures to your aunt, then you probably aren’t going to need to put an Athlon XP 3200+ in the system.  While faster is better, faster is also hotter—which leads to noise.

If the system is going to be your all out modified gaming machine, a processor will be a central core critical component and you’ll probably not want to go with less than an Athlon XP 2500+ Barton. They aren’t that expensive and they will provide a good amount of “bang for the buck.”

If the system is a CAD / DV system, then you could possibly look at dual processing (Athlon MP) or possibly an AXP-B 3000+ or even an AXP-B 3200+.

How fast should I go?

As with the previous system guide, I’ll use my own personal recommendations here, and keep in mind that it’s your system, build it the way you want it.

Grandma’s box to play Spider Solitaire – AMD Athlon XP 1700+

Internet Surfing – AMD Athlon XP 1700+

CAD / DV Workstation – AMD Athlon XP Barton 3200+ or dual Athlon MP 2600+

Gaming Boxen – AMD AXP-B 2500+ and up

Overclocking – The best overclocking chips seem to be the AMD Athlon XP 1700+, AMD Athlon XP 2100+, with the AMD AXP-B 2800+ also being a possibility.  Overclocking will be discussed later on.

Front Side Bus Speeds

Newer processors coming from AMD, including some of the high end Athlon XP series and all of the AXP-B processors, run on a higher FSB than the older more common 133MHz.  Excluding the Athlon XP 3200+ and the more rare Athlon XP 3000+, these processors use the 166MHz (double pumped “333MHz”) FSB.  How does FSB affect performance you may ask?  When it comes to Internet surfing or playing the occasional game of solitaire, you’ll see absolutely no performance difference between a 133MHz FSB processor and a 166MHz FSB processor.  This all changes though when you talk about SETI@Home, Folding@Home, or any other distributed computing project.  Because of the way these programs “crunch” data, they can make use of the higher FSB and benefit greatly from it.  Gaming boxes can benefit from a higher FSB as well – and if you’re going for a high score in a benchmarking program, the higher the FSB, the better.

Current popular AMD Processors:

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