CPU Page

So what's a CPU?  It stands for Central Processing Unit.  Many users erroneously refer to the whole computer box as the CPU.  In fact, the CPU itself is only about 1.5 inches square.  The CPU does exactly what it stands for.  It is the control unit that processes all* of the instructions for the computer.  Consider it to be the "brain" of the computer.  It does all the thinking.  So, would you like to have a fast or slow brain?  Obviously, the answer to this question makes the CPU the most important part of the computer.  The speed here is the most significant.  The processor's (CPU's) speed is given in a MHz rating (see Glossary).  Related topic:  Motherboard.

What To Look For:

• There is one basic thing to look for in a CPU, the MHz rating.  Obviously, the higher, the better.  If there is one part you are going to splurge on for your computer, make it the CPU.  A good rule to go by is getting a CPU that is 100 MHz within the range of the top speed CPU. 
• Bus Speed is another VERY important thing to look for (see Glossary for definition).  Currently 100 MHz is the most common bus speed.  Intel's Pentium II CPUs that are rated at 350 MHz or higher all run on the 100 MHz bus speed.  Previously the standard bus speed was 66 MHz.  Now we're getting into the 133 MHz bus speed of the Pentium III line.  This increase in bus speed is much more effective than an increase in CPU speed since it affects the speed at which many different components communicate with each other inside the computer.  I would highly advise getting a CPU that will run at the current highest bus speed, provided the motherboard you have (or are getting) will support that bus speed. 
• Internal Cache is the quick access "memory" that is on the CPU to hold recent data.  This memory is very important in speeding things up.  When comparing CPUs, you may want to look at how much cache the CPU has.  Be warned:  Intel's original Pentium II Celeron CPU has NO CACHE!  Oddly enough, in some applications it performs quite well, but other applications may cause it to perform like a plain old Pentium classic.  This chip is only practical if you are considering Overclocking, as it is very overclockable (at this point in time).  Reports are in of the 266 MHz chip running at 400+.  The newer Celeron "A" chips *do* have cache memory, and it is directly on the CPU, unlike the Pentium II.  Thus, it is very fast access.  This makes up for the fact that is has less cache than the Pentium II.  An overclocked Celeron A CPU will easily match the speed of a Pentium II CPU of the same clock speed. 
• You may also want to consider the additional instruction sets common to most of today's CPUs.  The Pentium MMX CPUs were the first to add such instructions.  MMX stands for MultiMedia Extensions and consists of a set of instructions to enhance multimedia on the PC.  It is worth noting that any of the Pentium II CPUs running at 333 or higher contain additional MMX instructions (only 2 I believe).  The Pentium III has new "KNI" instructions (thought the name is supposed to change) which are supposed to speed up various processes.  This is the main difference between the Pentium II and the Pentium III. 
• Buy from a dealer you KNOW you can trust.  Why?  Simply because there is a rapidly spreading trend going around where some dealers are "remarking" their CPUs.  For example, they may take a 333 MHz processor, remark it, and try to sell it as a 350 MHz processor in order to make more money off the CPU.

Recommendations:

• 6/16/00 Update - The new, higher speed P3s are actually beating the Athlons now (at the same clock speed) since the P3 cache runs at full CPU speed, while the Athlon cache only runs at a certain percentage of the CPU's speed.  Recommendations?  The Pentium III 550E is still a great overclocker, but you may want to try a higher speed variety now.  The 600E will also give you a good boost.  Or you can look to the much higher speed CPUs and do only a small amount of overclocking.  Combining this with one of the newer BX boards, PC133 RAM, and a GeForce (or GeForce II) video card will provide you with a very fast and reliable computer. 
• As for the Celeron II, I suggest avoiding it.  The 566 isn't a bad CPU in that it overclocks to 850 or 876, but the performance is comparable to a Pentium III 650 (which you could also overclock). 
• 4/24/00 Update - For those interested in the Athlons, you may want to wait a little longer.  The KX133 chipsets are out now providing better all around motherboards, which is a good thing, but the new Thunderbird and Mustang (Mustang is a mobile CPU) CPUs will be coming out soon.  AMD will even be going from a .25 to a .18 micron (Thunderbird will be .18) process with a .13 micron process not far behind.  This means cooler CPUs and faster CPU speeds (including great overclocking potential)!  Thunderbird is also the first CPU to use Copper interconnects, and is expected to be out sometime in 2000. 
  At this point in time though, the Athlon is the power chip to get (although you may have a little bit of stability issues).  AMD recently cut prices on this CPU line too, and it's now affordable all the way up to 900 MHz (1 GHz is too expensive).  Check pricewatch.com for prices.  The 700 and 750 speeds are the best to shoot for as they are overclocking to 800, 900, and even some to 1 GHz.  Not bad for the low price!  I would suggest using the NorthWind GFD (Gold Finger Device) card (an extra $50) to use to overclock the CPU.  You can get it here: http://trinitymicro.hypermart.net/.
  The new Celerons (AKA Celeromines) use the Coppermine core, but don't compare to the Coppermine in terms of performance.  If you're using an Intel CPU, stick with Coppermine (Pentium III - the P3E in particular). 
• 3/1/00 Update - The P3E is probably your best option now.  The 550 MHz part is probably one of the best to try.  They have been successfully overclocked to 682 MHz (using 124 MHz bus speed0 on most computers, and to 731 MHz on some occasions (133 MHz bus speed).  These speeds usually are hard to achieve without PC133 memory, and the video card will usually cause problems unless you are using a motherboard with 1/2 AGP divisors (NOT present in the BX chipset).  If you are using a BX based motherboard, then 682 MHz is likely as high as you will be able to go reliably unless you have a video card that can tolerate the high speed (I am unaware of any video cards that will consistently run at the 2/3 of 133 AGP speed). 
• 11/13/99 Update- P3, P3B, P3E, P3EB???  It's not that confusing really. 
  -The P3 is the original Pentium 3. 
  -The P3B is a Pentium 3 that runs at 133 bus speed.  I suggest waiting until the i820 chipset is ready since 133 bus speed can't be run reliably on the BX chipset motherboards, and I wouldn't recommend the Via Apollo Pro 133 chipset.  There's not really much of a point in getting this particular CPU. 
  -The P3E is the "Coppermine" Pentium 3 that is built on the .18 micron process.  What does this mean?  All you need to know is that it provides cooler running, higher speed possibilities, and perhaps greater reliability.  This also makes it a better overclocking CPU  :)  This CPU runs at 100 MHz bus.  In addition to the bus speed difference, the P3E has other enhancements, the most important of which is 256k of full speed on-die cache.  This is much like the Celeron cache which runs at full CPU speed, except it's twice as much of it.  This provides a significant speed boost and finally sets the Pentium 3s apart from the Celerons. 
  -The P3EB just has both features - runs at 133 bus speed, is on a .18 micron die, and has 256k full speed cache.  This is the one to get once the i820 is available. 
  -If you want a Pentium 3 right now, it would be best to get the P3E, but you may want to wait for the i820 and get the P3EB. 
• So what speed?  If you want the P3EB, I would suggest the 533 or 600.  The higher speeds are overpriced. 
  If you want the P3E, you wouldn't want to go higher than the 650 because even that one is pretty expensive. 
  If you want the P3, the 450 is a good overclocker and is cheap.  The 500 is pretty cheap now too.  You could also consider the 550 or 600. 
• 10/10/99 Update- Celeron 366 CPUs are doing well now.  The majority of them will overclock to 550 MHz!  I recommend this CPU for those trying to keep the cost down. 
  For those with a little more money to spend, the Pentium III 450 MHz CPU is now quite affordable and overclocks quite well.  Most I have seen will run at 558 MHz or higher...
  ATHLON?  Here's my opinion on AMD's new CPU.  It is a great, very fast CPU; even faster than Intel's Pentium III CPUs.  BUT, I don't trust it yet and recommend that others wait awhile too.  In my experience (and many others) the AMD CPUs paired with the Via and Ali chipsets have been very problematic.  Personally, I would rather have a fast CPU that is very stable than a very fast CPU that is going to be a pain to work on and unstable.  Until these CPUs and motherboards have a good track record going, I will avoid them. 
  So far, the reports aren't good.  There have already been some compatability issues, and one friend of mine wasn't even able to get Windows 2000 to boot! 
• 7/1/99 Update- The Socket Celerons (PPGA) are now the chips of choice as they are easier to find and tend to overclock better too.  In addition, they are quite a bit cheaper!  The 333 retail Celeron PPGA is my choice.  The 300s are getting very hard to find and the 333 will likely go to 500 MHz. 
  Also, the Pentium III 450 is starting to look like a really good overclocking CPU, and it has really come down in price.  You may want to consider spending the extra money.  Reports are in of it running at up to 600 MHz.  Note that this is only achievable with a good motherboard and good RAM (PC133 preferably).  It's best if the motherboard supports a 1/4 divider for PCI speed (and 1/2 for AGP). 
• 1/1/99 Update- Feel free to read the older paragraphs below, but plain and simple, the best choice in CPUs right now are any of the Celeron CPUs with cache.  Intel planned these CPUs as a low-end, budget system CPU, but they have proven to be nearly as fast as the Pentium II line.  When overclocked, they are just as good as any Pentium II at the same speed rating.  Roughly 90% of the Celeron 300 A CPUs for example, will run stably at 450 MHz or greater, yet they cost roughly a third of the price of the Pentium II 450... 
• This page will have the most broad recommendations since there are so few CPUs to choose from. 
• First you need to decide what brand you want to use.
  Currently, desktop CPUs are manufactured by 3 primary companies; Intel, AMD, and Cyrix.  So which company is the best?  This question is open to different interpretations.  Obviously, Intel is the most standard (currently).  Are Intel's processors the fastest?  Not necessarily.  Depending on what kind of games/applications you are running, Intel may not be the fastest.  Highly demanding games, such as the Quake series, are very dependent on what is known as FPU, which processes floating point numbers (decimals).  Currently, Intel's Pentium II processors are the fastest regarding FPU.  If all you wanted to do was play games similar to Quake, go Intel. 
  On the other hand, if you are merely concerned with Windows business applications, Cyrix's 6X86 MX processors may be superior, if not just for the price difference.  If you use both games and business applications, AMD's K6 (and K6+3D) may prove the better choice.  Though I in no way desire to promote Intel's near monopoly, I do feel Intel's CPUs are the most viable option in terms of support, speed, and reliability. 
• Next, you need to decide what speed you want.
  So should you buy the CPU with the highest MHz rating?  Depends on how much money you have and if you want the best.  To be practical though, you may not want to buy the fastest CPU out there.  Consider Intel's Pentium II CPU's running at 350 and 400 MHz.  Let's imagine those were the fastest two CPUs out there.  In general, the 400 is going to be MUCH more expensive than the 350.  It may be better to buy the CPU that is one or two steps behind simply because of the fact that the top CPU is ALWAYS going to be much more expensive than the ones below it, and the difference in speed is NOT equal to the difference in price.  Also consider that no matter what, in two years, you're computer will be viewed as slow relative to the newest computers.  In other words, if you want to spend the money on the best, consider that it won't be the best for long. 
• One last recommendation here; I would highly advise against buying a generation old CPU.  By this I mean don't buy a Pentium MMX since the Pentium IIs are out.  If so, you are dooming yourself to early obsolescence, since you are buying yesterday's technology. 

• My number one pick: Intel's PPGA Celeron 366 CPU.  This CPU can be overclocked to 550 MHz.  If you don't want to try overclocking, my recommendation stands, except that I would advise on getting the 433 or 466 MHz Celeron.  It will perform almost exactly the same as an equivalent speed Pentium II, perhaps slightly slower, but not enough to justify the price difference  ;)

• Second recommendation is Intel's Pentium III 450 MHz CPU as it is a fast CPU as is, and it also overclocks well (to 558 MHz w/o problems).