UPDATE:  I found a most excelant article on Pentium 4 and Athlon.  In fact, it pretty well covers the history of x86 processors in detail...  It's several pages, very in-deapth, and if you read it carefully you will probably walk away with a much better understanding of the principals guiding speed in modern (and older) CPU's and programs.  Check it out, if you want to.  ALL INTEL'S BASE ARE BELONG TO AMD !!

Alrighty...  I know there are about a million articles like this on the web, but here's my take anyway.  (I work for Intel.  I've got a good perspective on things.)  For those new to this, AMD is the chip producer that manufactures the Athlon (T-Bird), Duron, and K6 microprocessors.  They are the arch enemy of Intel, producer of the Pentium, Xeon, and Celron microprocessors.  Let me set the stage for you.

Intel had been leading the x86 (90% of computers out there) for years.  Cyrix (yet another chip manufacturer) and AMD have been battling with Intel for years.  Cyrix, in a word, makes the Volkswagen of microprocessors.  (I mean that in a bad way.)  Intel has always been top dog.  AMD has always fallen somewhere in the middle.  For years, AMD couldn't quite top Intel's speed, stability, and support.  (Thus the term 'no one has ever been fired for buying Intel.')  All that changed around the beginning of 2000.  WHAT YOU SAY !!

AMD came out with a processor called Athlon to compete with Intel's Pentium III (what most new computers are running.)  Athlon quickly ramped up to speeds greater than Pentium III.  Initially, Athlon was plagued with power consumption and compatibility problems.  (It's a power hog.)  After a second release of motherboards, these began to disappear and Athlon started gaining ground on Pentium III's market share.  Athlon quickly passed Pentium in terms of speed and the battle was on.  For months, Intel and AMD one-upped each other in the battle for the highest Mghz.

[NOTE:  A quick note on processor speed.  Processors are rated by Mghz.  How many 'calculations' it can do in a second.  However, if a one processor is smarter than another, it can take less calculations to acheive the same results.  This is known (sort of) as core efficiency.  AMD processors have more efficient floating point math and about equal integer math to Intel's Pentium III.  Pentium III has better branch prediction.  (Don't get me started on what branch prediction is.  If you really want to know, email me.)  Thus, at the same clock speeds, Athlon will usually go faster than Pentium III.  (Though Pentium III will give you a few more frames per second on games.)  Just wanted to note that.  It's surprising how many people judge speed by Mghz alone.  (Imacs only run at about 400Mghz and their damn fast.)]

So over the months, the Mghz was ramped up on the CPU's (microprocessors) and prices fell faster than Bill Clinton's pants.  In the end, the Pentium III showed it's true age.  It's older core (the thingy that does all the real work) couldn't keep up and it peaked at 1100Mghz.  (As of the end of 2000.)  AMD pushed theirs to 1200Mghz and it will probably go even further in the future.  (I'm guessing it will max around 1500 to 1700.)

Enter Pentium 4.  Pentium 4 is...  well...  odd.  Pentium 4 is the titanic of x86 CPU's.  (x86 = any windows machine.)  Pentium 4 started at 1400Mghz.  That's fast, right?  Well.  Sort of.  It really depends on what you look at.  Pentium 4 was designed to take advantage of programs writen for IT.  (So programs must be built with Pentium 4 in mind or they will probably run the same or worse on it.)  And here's another interesting tidbit.  Pentium 4 has a pipeline that is more than 20 stage.

[NOTE:  A pipeline in how many points a calculation has to go through to get from one end of the chip to the other.  AMD's Athlon had around 6.  Pentium III had under 10.  Pentium 4 has over 20.  More stages = less speed...  usually.  Some of it depends on what program you're running.  This is why people are having so much trouble comparing Pentium 4 to other CPU's.  It's not like the other CPU's.]

So as of the writing of this article, which is better?  Well...  I work for Intel.  I'd buy and Athlon or Duron.  (AMD.)  Intel processors are to expensive for my taste and Pentium 4 only works with RDRAM.  (More on that in another article.  You can read about RDRAM on ArsTechnica.  They have a very good in-depth article about it.)  Consider this.  As of December 22, 2000, you can pick up an 800Mghz Duron for 85$ (pricewatch) and that price will surely drop.  Also, if you're really eager to get [H]ard core, you can overclock that bad boy to upwards of 1000Mghz.  That's unheard of!  That's dirt cheap.  Pentium III will get you slightly better gaming (1 - 5 frames per second) but it's just not worth it to me.  And there's another thing about AMD's Athlon worth noting before you finish.

AMD was looking ahead when they designed their Athlon.  Here's why.  Pentium III runs with a 100Mghz FSB (Front Side Bus.  This is explained very well at ArsTechnica.)  What that means is that data can only enter the the CPU at 100Mghz.  It's then calculated at whatever speed the processor is running.  So if the processor is churning out answers faster than questions can come in, you're not taking advantage of all that processor speed you paid for.  But...  AMD's Athlon runs at 100Mghz (and now 133Mghz) DDR.  (DDR means Double Data Rate.)  Skipping the technical explination, this means AMD crams twice the data in per second.  So they're effectively getting a 200Mghz Front Side Bus.  (Or 266Mghz on the new ones.)  That's fast, and it helps.  You're a lot less likely to max out your bandwidth coming into your CPU.  (That's a good thing.)  And the new AMD runs faster RAM as well.  (That's good to.)  And the last I heard was that it's still cheaper than Pentium III.  (Note:  I still think Pentium III is a good chip.  I'm not biased here.  You'll get good results if you use Pentium III or Pentium 4.)

Now, there's one more chapter to the saga before you make up your mind.  Pentium 4.  Always throwing things up in the air...  It runs at an effective 400Hghz Front Side Bus.  That's really really fast and for games and video editing, you can tell the differance.  But...  There's a draw back.  1.  It uses Rambuss Ram.  (Repeat after me.  Rambuss is the devil.  Rambuss is the devil.)  I am biased against them.  Besides the fact that they're suing just about every other chip company out there, their ram isn't 'all that'.  And it's really expensive.  Intel is in the process of divorcing Rambuss.  I'm not sure where that will put Pentium 4 when they go to another type of RAM.  (A questionable upgrade path.)  And as for myself, I won't pay that much money for so little performance increase.  But if you're into video editing or 3D stuff, and you constantly have thoughts like 'Gee.  What should I do with that big stack of money I've got in my living room.'  Go for it.  Get yourself a Pentium 4.

In the end, though, I think AMD's starting to come out on top.  Only time will tell, and Intel isn't going to fall down anytime soon.  Which should you use? I leave that to you.  Email me if you want more information.  Good luck!

[NOTE:  Just to leave you feeling uneasy about the future.  Intel's next chip will have a 64 bit code set.  Any program written to take advantage of it will probably run really really really damn fast.  Any program that only uses that 64 bit architecture will only run on that processor.  (Scary thought.)  I believe that AMD is making their own 64 bit code set, but I'm not certain.  Things are getting interesting in the future of chip making.  Pop over to ArsTechnica for more info, or email me if you want.  And thanks for reading.]