Battle at 500MHz: Athlon vs P3 vs Celeron

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.