Since all of Intel’s desktop processors currently in production are based, in one form or another, on the 0.18-micron Coppermine core, they can all be expected to be capable of achieving similar clock speeds.
The part that all other 0.18-micron Intel CPUs have been derived from is the Pentium III based on the Coppermine core with 256KB of on-die L2 cache operating at clock speed. As we mentioned above, the Coppermine Pentium III is officially available in speeds ranging from 500MHz to 1GHz, although the latter speed is only available in limited quantities. As we’ve already proven in our series on Overclocking the FC-PGA, the ability of the Coppermine Pentium III core to hit such high frequencies makes overclocking the 500 – 600MHz parts very tempting since they can, with relative ease, attain very similar frequencies in the 667 – 800MHz range simply by increasing the FSB frequency.
But what does this have to do with the recently released FC-PGA Celeron processors?
The new Celeron processors are based on a variant of the Coppermine Pentium III core. Internally, they are based on a core known as the Coppermine128, which refers to the 128KB of on-die L2 cache they are outfitted with versus the 256KB that is on the regular Coppermine Pentium III core.
While there are more differences than just having 1/2 the L2 cache that’s present on the Pentium III, the most important thing to keep in mind here is that, because the new Celerons are based upon a variant of the Coppermine core, they can be expected to have similar yields and thus attain similar operating frequencies.
Taking this comparison one step further, with the exception of the extremely rare 1GHz Pentium III, the Coppermine Pentium III CPUs are available in clock speeds up to 866MHz. Presumably, Intel is seeing a high enough yield on their 0.18-micron Coppermine core to release it in quantity to the public at 866MHz. This also indicates that the Coppermine128 should also be able to hit that 866MHz mark since the core it is derived from, the Coppermine, is currently able to do just that.
The beauty of this situation is enhanced even further when you look at the currently available FC-PGA Celerons (based on the Coppermine128 core): the 533A, 566, and 600MHz parts. These 66MHz FSB parts have clock multipliers that, when paired up with a 100MHz FSB, result in a final clock speed in the 800 – 900MHz range, which is exactly where the highest yielding Coppermine Pentium IIIs fall.
Last December, we overclocked the FC-PGA Pentium III with great success; now, let’s see how the FC-PGA Celeron fares.