Click here for detailed descriptions of all of the tests run.
Click Here for a detailed description of the four visual test modes used in the Quake 3 tests.

You can easily make the argument that the performance difference between the three processors comes from the Athlon's 200MHz FSB versus the 100MHz FSB of the Pentium III. However we have also learned that, in a single processor system the bandwidth offered by the 100MHz FSB is not as great of a limiting factor as we might be made to think it is.

The earliest benchmark reports of the 133MHz FSB and the Pentium III don't indicate the stellar performance increase that some manufacturers were hoping for. While the situation is a completely different one when you take more than one processor into account, the performance differences among the three processors compared here cannot be attributed to the differences in FSB frequency alone (the part FSB frequency plays is a very small one in comparison).

With the two Intel CPUs sharing the same architecture, the superior design of the Athlon shines unsurprisingly clear among the three processors, especially in FPU intensive applications. While it is very odd to be praising AMD for a superior FPU, the truth stands that the P6 core is outdated in comparison to AMD's creation and thus the raw FPU power of the Athlon is greater than that of both of the Intel solutions.

Without getting into debates over architecture and design, there remains one basic factor that contributes to the performance or lack thereof with these three CPUs. That factor? The cache.

The two Intel processors are quite similar because are both based on the same core. However their differences grow out of their L2 cache configuration. The Pentium III (and the Pentium II) makes use of a 512KB L2 cache located off the processor operating at 1/2 of the clock speed of the CPU while the Celeron includes an integrated 128KB L2 cache running at the clock speed of the CPU. What this brings about is the classic debate of whether a larger but slower L2 cache is better than a small but faster L2 cache. The true answer to that question depends on the type of application that you're using to assess what is "faster."

For business applications that can fit in the smaller 128KB L2 cache of the Celeron (the two processors share the same 32KB L1 cache so we'll leave that comparison out of this), the Celeron will be the faster processor. This makes the Celeron the better processor for your basic set of business applications since they don't need the extra 384KB of L2 cache the Pentium III offers. At the same time, in situations where the application(s) do not fit into the 128KB L2 cache of the Celeron, they must go to the system memory which is obviously much slower than the L2 cache. If they do happen to fit into the 512KB L2 cache on the Pentium III, then those applications (whether it is 1 or more than 1 application) will experience greater performance on the Pentium III platform.

Outside of business applications, we have a number of high-end applications that can experience similar performance differences. As you'll be able to see by the benchmarks, there are some high-end applications that benefit from the larger L2 cache while others don't exhibit a noticeable difference in performance.

The most noticeable difference comes when you are running configurations of dual Celerons versus dual Pentium IIIs. What you will notice in those situations is that in situations when quite a bit of data is being manipulated (i.e. 3D rendering) the larger L2 cache of the Pentium III setup will be favored over the smaller but faster L2 cache of the Celerons. The severity of the performance difference is increased, in favor of the Pentium III, by the slower 66MHz FSB of the current generation of Celeron processors.

On the reverse side of things, if there isn't a lot of data manipulation taking place then there will be relatively no difference between the dual Celeron setup and the dual Pentium III setup.

So what happens when we add the Athlon to this Cache comparison? The Athlon is a unique creation in that it's L1 cache is four times the size of the Celeron/Pentium III and also features a L2 cache equal in size to the Pentium III. What we end up dealing with is a processor that has very little difficulty fitting an entire business application within its L1 cache. And for applications that cannot reside completely within that 128KB the processor also boasts a full 512KB of L2 cache operating at 1/2 its clock speed to rely on.

With the Athlon, we have the best of both worlds: a large L1 cache to help in business application performance and a large L2 cache to help in high-end application performance. Both of these pave the way for a strong multiprocessing platform with the Athlon.

It's no surprise that the business application performance of the three CPUs is very similar and much less of a factor than it used to be back when L2 cache operated outside of the CPU clock frequency.   All three chips are winners here.

The SYSMark 98 suite combines many more benchmarks into the test including a few 3D rendering applications and some more content creation applications (Click here for detailed descriptions of all of the tests run) and thus tilts the performance in favor of the Athlon.

* These applications are a part of the Intel Performance Measurement Utility Suites
Numbers reported in the above table (with the exception of Winstone) are time in seconds, lower is better

* These applications are a part of the AMD Benchmark Suites
Numbers reported in the above table are time in seconds, lower is better

Numbers reported in the above table are time in seconds, lower is better

Numbers reported in the above table are time in seconds, lower is better

Numbers reported in the above table are time in seconds, lower is better

Numbers reported in the above table are time in seconds, lower is better

Quake 2's crusher.dm2 demo is still a powerful way of conveying gaming performance as the test taxes most systems quite heavily.  Even the powerful Athlon 500 only pulls away with just under 60 fps in this demo at 1024 x 768.

The Quake 3 test demo restates the fact that the Athlon has a superior FPU than both of the competing Intel parts, but at the same time it also indicates that the difference in gaming performance between the Celeron 500 and the Pentium III 500 is minimal.  Definitely not worth the difference in cost.

Half Life is a very CPU dependent game and using it's Direct3D mode we are able to compare the three processors in another demanding environment.  The results are similar to the Quake 3 results with the Athlon 500 coming out on top, followed by the Pentium III and Celeron, which scored a few percentage points of each other. 

As we learned in our September 1999 Desktop CPU Comparison, Expendable produced very close results between the Pentium III and Athlon platforms but the Athlon has the edge once again over its Intel competitor.

The performance advantage the Athlon holds over the Pentium III and Celeron under NT is considerable.   The performance difference between the Celeron 500 and Pentium III 500 is somewhat noticeable.  Keep in mind that the Celeron 500 offers 89% of the performance of the Pentium III under High End applications (according to the Winstone results), is that extra 11% worth the price difference to you?

With the wider range of applications and the inclusion of 3D rendering test, the performance gap extends in favor of the Athlon in the SYSMark 98 tests. 

The true power of the Athlon's FPU is seen in the 3D Studio MAX tests where, clock for clock, it dominates the Pentium III offering performance on par with that of a dual Pentium III 500 system.   The benefits of the Pentium III's larger L2 cache can be seen here as well. 

* Time in seconds, lower is better

Price

In order to compare the three processors based on price, we did a little bargain hunting and came up with some interesting results. The first thing that you have to keep in mind is the difference between an OEM or Tray processor and a Retail or Boxed processor.

An OEM (Tray) processor is shipped by the manufacturer to distributors in trays (hence the name Tray) and generally carries a 15 to 30 day warranty on the CPU itself. The OEM processors do not come with a heatsink or fan and, depending on who you ask, are less overclockable than their Retail/Boxed counterparts. OEM processors also have the disadvantage of potentially being remarked as they do not come prepackaged or sealed from the manufacturer for sale. This could pose a problem with Athlon processors as they are not clock locked. With the 500MHz Athlon being compared here the problem isn't a problem at all since the Athlon 500 is the slowest Athlon available but it may be a much bigger problem with the faster 600 and 650MHz parts. The Intel CPUs are less likely to be the victims of remarking (especially the socketed Celerons) as they are shipped directly from Intel as clock locked CPUs, meaning their clock multiplier cannot be modified by the usual means. As of now, no one has been able to break the clock multiplier lock on the Celeron/Pentium III and publicly disclose their methodology.

On the up side, an advantage of an OEM processor is that it is sold anywhere from 5% to 20% below that of a Retail/Boxed part because of the shorter warranty period as well as the lack of a bundled heatsink/fan combo.

A Retail/Boxed part comes boxed from the manufacturer to the distributors and carries a much longer warranty from the manufacturers themselves. These processors are arguably more overclockable than their OEM counterparts (there was quite a bit of debate as to whether or not the retail Celeron 300As made it up to 450MHz more reliably than the OEM Celeron 300As) and do ship with a retail heatsink/fan combo. The only problem here is that these processors obviously cost more due to the two factors we just mentioned, but some users are willing to pay the added cost to get the longer warranty and lesser chance of their processor being remarked.

AMD currently does not offer a retail/boxed Athlon processor, so only the Intel Celeron/Pentium III were available as Retail/Boxed processors when we tallied up the prices of the processors from the ten cheapest vendors on Price Watch.

We took an informal survey of the ten cheapest vendors on Price Watch and averaged their prices together for all three CPUs. We separated Retail and OEM prices into two different categories.

Unsurprisingly, the Celeron 500 is the obvious winner. The physically smaller chip costs less to manufacturer than its bigger Slot-1 counterpart, and it is sold as a "low-end" CPU from Intel so it makes perfect sense that the Celeron would be priced considerably lower than either of the two competitors.

The OEM Celeron 500 seems to be a very good buy at an average price of $145.50 especially since the retail chip won't buy you much more than a heatsink/fan at an added $25.50. It is interesting to note is that the price of the OEM Athlon 500 is less than that of a Retail Pentium III 500. It seems that although AMD never intended to compete with Intel on price with the Athlon they are doing quite well.

It should also be mentioned that the OEM Pentium III 500 has no problem coming in a full $20 cheaper than the OEM Athlon 500. The true question here is, does the Athlon 500 outperform the Pentium III 500 by a large enough margin to warrant the $20 price difference? Better yet, do both the Athlon 500 and the Pentium III 500 outperform the Celeron 500 by a large enough margin to warrant the $85 - $100 difference?

Look at the performance numbers once again. Is an extra 20 fps in Quake 3 worth another $100? Is an extra 10 fps worth $85? If you realistically look at what you're getting for your money and what you truly need, the Celeron 500 seems to cut it just fine. Then again, there are those that have already set aside $300 for a CPU that have no problem going after the Athlon or the Pentium III. Do you have that extra $85 - $100 to kill?

Also keep in mind that the cost of owning the Athlon 500 involves a bit more than buying a $250 chip, the current crop of Athlon motherboards on the market are generally $40 - $60 more than the Slot-1/Socket-370 boards.

With a total of 6 known motherboards that are due out for release before the year's end for the Athlon processor (Gigabyte, MSI, and ASUS being the most popular brand names), you can't honestly say that the Athlon processor is receiving the industry support it needs to succeed. Hopefully with the introduction of the ASUS Athlon motherboard and the upcoming Tyan motherboard (which should be a very promising solution according to Tyan) things will change, but as of now the Athlon loses out in terms of industry support.

Granted, AMD just released the Athlon under two months ago and industry support can't be expected to be nearly as great as it is for the two contributions from Intel that have been available for quite some time, but the fact of the matter is that if you're in the market for a new computer today you aren't going to be too forgiving if you can't get the processor you want because there are no good motherboards available.

In terms of software optimization, the Athlon specifically isn't boasting much support from software manufacturers with programs that are already on the market, however there are quite a few titles that are in the works with Athlon specific optimizations. For example, Naturally Speaking 4.0, a voice dictation program, supposedly has specific optimizations for the Athlon processor.

On the other hand, AMD's 3DNow! instructions have been around since mid-1998 and have gained quite a bit of industry support. The Athlon's support for AMD's 3DNow! instructions give it a great deal of power in the industry in terms of support, but, the big question here is, when you go out to buy a piece of software, do you look to make sure it has 3DNow! support before buying it?

Although motherboard support for Socket-370 processors isn't nearly as great as the support for the Slot-1 platform (Slot-1 has been around for 2 years, Socket-370 has been around for less than one) the ability to use a Socket-370 CPU with a converter card in a Slot-1 motherboard opens up the Socket-370 platform to just about every motherboard you could possibly dream of. An added $15 card allows a Celeron 500 owner to go after an ABIT BE6-II or an AOpen AX6BC Pro instead of the limited Socket-370 motherboard choices he/she would normally have.

At the same time, if you're looking to construct a cheaper system, there are quite a few microATX Socket-370 boards based on the i810 chipset (including a few based on the BX) that offer a very low price tag. In essence, the Celeron supports your favorite Slot-1 boards, all Socket-370 boards, and offers a greater variety of choice for motherboards based on the i810 chipset. This is a definite plus for the OEMs and System Integrators looking to build low-cost systems as well as those of you that are looking for cheap entry-level systems.

Since Socket-370 motherboards don't really have any features to offer that the Slot-1 motherboard don't already support, the Slot-1 Pentium III isn't at a loss by not supporting the interface. The only factor which gives the Celeron the edge over the Pentium III here is the lack of cost effective i810 based Slot-1 motherboards. However, there are a few that are not nearly as popular as the Socket-370 i810 boards.

The Pentium III's SSE support is fairly laughable right now because it was made public after AMD's 3DNow! had already gained momentum and SSE doesn't offer that big of a real world improvement in most cases. This brings up the same question as before: When you go out to buy a piece of software, do you look to make sure it has SSE support before buying it?

Since both the Athlon and the Pentium III have added instructions that require special consideration from the programmers in order to gain any performance boost from them, and neither 3DNow! nor SSE offer a huge performance increase for either of those processors, the tangible benefits are limited.

If you aren't going to be overclocking your CPU then you can just skip this section entirely. However if you are interested in seeing what you can truly squeeze out of your processor, then this section is very well worth it.

What good is a Celeron 500 if you can already push your 366 to 550MHz? That is the very principle that overclocking is based on, squeezing the extra ounce of performance out of your CPU so you don't have to pay for what you can get for free. When comparing the overclocking potential of all three processors we made sure not to take into account super cooling setups simply because, if you're going to spend $50 - $100 on an elaborate cooling fan setup both for your processor and for your case you're better off just buying the faster processor.

The first Pentium III 500 we took a look at back in February of 1999 had no problems hitting the 560MHz mark, provided that you used the 112MHz FSB. The most recent 500MHz parts seem to have similar success with quite a few users claiming the ability to hit 585MHz (117MHz FSB) with a bit of added cooling. Especially with all of the FSB settings of some of the newer BX motherboards such as the BE6-II with its 1MHz FSB increments, the possibilities are endless.  However we can safely say that the 560/585MHz marks are the sweet spots for the Pentium III 500 without going overboard in terms of cooling.

At 560/585MHz, the business/office performance of the Pentium III is closer to that of the Athlon with a slight 2% - 5% advantage in favor of the Athlon.  Additionally, the gaming performance of the overclocked Pentium III still lags behind the default clocked Athlon 500 as well and the raw FPU performance (i.e. 3D Rendering) of the overclocked Pentium III still takes a back seat to the unoverclocked Athlon. The overall system performance of an overclocked Pentium III (560/585MHz) is about a few percent slower than that of the default clocked Athlon 500, so even if you overclock the Pentium III 500 the Athlon still holds a pretty hefty performance advantage.

Overclocking the Celeron is a much trickier situation because it uses such a high multiplier (7.5x in the case of the 500) and still uses the 66MHz FSB. Very few BX motherboards provide for FSB settings other than 75 and 83MHz but the ones that do offer quite a bit of flexibility. Once again, citing the BE6-II example where there are a total of 20 FSB settings under 100MHz including 66MHz, the Celeron 500 has a much greater chance of being overclocked. But how high can it realistically go? Using the 75MHz FSB, the 563MHz clock speed is the most realistic setting for the Celeron 500. At 563MHz the processor is faster than the Pentium III 500 in all tests, though it still loses out to the Pentium III at 560MHz in some high-end tests thanks to the Pentium III's larger L2 cache.

The Athlon is an entirely different situation because, as of now, overclocking the CPU requires a somewhat complex method of modifying the PCB by adding and/or removing resistors. For most normal users, this is too risky (especially when you are lucky enough to have an Athlon) and thus leaves overclocking the Athlon a very dangerous possibility for now. However, for those of you interested in getting the most out of your already high performing parts, Tom's Hardware Guide has the entire how-to on overclocking the Athlon and the general consensus on the results of overclocking the Athlon 500 seems to indicate that reaching the 600MHz performance level isn't a stretch at all. At 600MHz the Athlon can't be beat by either of the two Intel processors regardless of whether or not they are overclocked.

Of the three processors, the Athlon 500 gives us the most well rounded performance and the Celeron 500 gives us the most cost effective performance. So what processor is right for you? One consideration we did not take into account until now was the future upgrade paths you will be left with after pursuing any of these processors.

With the Pentium III being available only in a Slot-1 interface you'll have to do a bit of estimating to see how much longer the Slot-1 platform will be around. Chances are, after the end of this year, Slot-1 will quickly begin to die off.

The new Pentium III B (133MHz FSB) and Coppermine processors will be available first in the SC242 (Slot-1) interface, but there will be a sharp trend towards Socket-370 and the new Socket-418 towards the end of this year and on into 2000. This move away from Slot-1 with all of the Pentium III processors will probably closely mirror the move away from the Slot-1 platform for the Celeron CPUs that we experienced around the release of the 433/466MHz Celeron parts.

Intel's reasoning behind the move away from Slot-1 is simple: a socketed CPU is much cheaper to manufacture than a CPU stuck on a PCB like the current Slot-1 Pentium III processors are. Case in point would be the price advantage the Socket-370 Celeron processors hold over the rest of the Intel CPUs available on the market today. Don't expect the Slot-1 market to have a bright future after the end of this year.

With Intel phasing out Slot-1, what about the Celeron's Socket-370 interface? The exact details of this implementation are still quite a bit sketchy but you can expect to see the Socket-370 interface to stick around much longer than Slot-1. The current expectation is to see a new generation of Socket-370 motherboards hit the market for the next generation of Socket-370 CPUs, but backwards compatibility with existing CPUs and vice versa has yet to be determined. The current Celeron core will probably last throughout the end of this year and into early next year when it is killed off by the release of the next-generation Celeron CPU, the Coppermine 128. Coppermine 128 will be the first 0.18 micron processors made for the low-end systems by Intel and will feature the same 128KB of integrated L2 cache that the current Celerons do plus the SSE support currently only offered by the Pentium III.

Since it was just recently introduced, the Athlon has bright future ahead of it especially if you purchase the Athlon 500 now. There are already three faster processors that pave the way for your upgrade path with the Slot-A (Athlon) platform, the 550, 600, and 650MHz Athlon parts. You can expect to see both 700MHz and 750MHz Athlon parts before the end of 1999 and this isn't taking into account the potential for overclocking those faster parts.

Just like Intel's Slot-1 platform, Slot-A has got to go. Intel has already proved that a integrated L2 cache is a viable alternative to the external L2 cache of the Pentium III/Athlon processors. They have also proved that it is cheaper to manufacture a single chip versus a chip soldered onto a PCB (as if we didn't realize that the first time we saw a Slot-1 processor), so it would make perfect sense for AMD to follow in Intel's footsteps.

Will we see a "Socket-A" from AMD? Probably not in the near future but it is a possibility to keep in mind. With the move to a 0.18 micron process it would make a lot of sense for AMD to drop the clunky Slot-A in favor of a more cost effective single chip solution just like Intel is doing with Slot-1. Will they? For once, let's hope that AMD does follow Intel's lead.

If you're buying a computer today and don't want to be kicking yourself for months to come strongly consider not going all out and, instead, picking up a decent Celeron 500 system with a TNT2 or a Voodoo3 (2000). This isn't an "Intel-biased" recommendation but, rather, rather a cost effective recommendation. Why? By the end of October you'll be wanting the latest and greatest from either of the two manufacturers, and a $160 investment in a Celeron right now is much easier to leave behind than a $240+ investment in either the Athlon or the Pentium III.

The reason to stay away from the Athlon if you're on a budget now is that the current state of Athlon motherboards is quite disappointing. If you absolutely must have an Athlon today, go after the FIC SD11 Motherboard because it is the only one that is available in decent quantities and after a couple of weeks of testing it does seem like the most reliable solution out there right now. Be sure that if you do buy an Athlon + FIC SD11 combo from anyone that you get the vendor to sell you a power supply (or a case + power supply) that they have verified works with the combo. There have been a number of problems related to Athlon motherboards and power supplies so make sure that your vendor takes the responsibility if your system doesn't work because they used a cheap power supply. The AMD recommended power supply list includes the following:

• Turbo-Cool 300ATX
• American Media CWT-300ATX
• Emacs AP2-5300F-RV2
• Astec SA302-3515-980
• Enlight HPC-250G2, A0-01
• Sparkle FSP250-61GN
• Enhance ATX-1125B
• FSF Group Inc FSP 250-61GN
• Delta Electronics Inc 200PB-103A
• Powerman FSP300-60GT

Although not a part of that list, from the personal experiences in the AnandTech lab, the Seventeam ST301-HR power supplies seem to be on of the best solutions (picture upper right). They are difficult to find but, if it makes the search any easier, they are the same power supplies used in the Kryotech systems (Kryotech knows their power supplies) and they seem to work quite well with the Athlon setups I've tested so far. That's just a small recommendation.

The reason to stay away from the Pentium III is because of the imminent release of the Pentium III B as well as the upcoming Coppermine processors in the course of the next 4 - 6 weeks. The basic laws of marketing state that whenever a new product is released, the prices of older products are pushed down, so you'll be kicking yourself if you spend money on a Pentium III 500 now and it drops another 20% in price because of new product releases. Since the Celeron isn't competing directly with the upcoming CPUs, don't expect Celeron prices to be affected too dramatically by the new processor introductions. Also with the onslaught of new chipset introductions for the Slot-1/Socket-370 platforms this quarter, a motherboard purchase now may leave you desiring something else in just a few weeks time.

The most intelligent decision now would be in favor of the Celeron.  While it may not be the fastest, the thing to keep in mind here is cost efficiency. If you don't care about cost, then the Athlon is the next best pick because it is just about the same price as the Pentium III 500 but delivers performance on-par with or greater than a Pentium III 600 in most cases.