The new “flip chip” Intel Celerons come in speeds from 533 MHz to 700 MHz and have a design very similar to the FC-PGA Intel Pentium III Coppermines. This design actually hearkens back to the original Mendocino core, which Intel introduced with the Celeron 300A. Instead of having the L2 cache absent or off-chip on the PCB, these Mendocino processors incorporated the L2 cache onto the processor die itself. The Pentium III Coppermine processor followed this format, but increased the L2 cache size to 256K, along with adding several enhancements. The Celeron 533A-700 processors use the same basic core as the Pentium III Coppermine, and gain all of the native enhancements such as the 0.18 micron process technology, a full-speed 256-bit L2 cache, SSE extensions, improved cache latencies, along with the transition to the FC-PGA processor package. Although the 128K of L2 cache remains consistent with the previous Celeron line, adding in SSE support and lowering the die size to 0.18 micron really gives the new Celerons a performance and overclocking edge over their predecessors and truly makes it a next-generation processor.

So if these two processor designs share a similar core, then what are the actual differences between them? The new Celerons are much the same as the Pentium III Coppermine chips, with a few variances. The most apparent of them is the 128K of L2 cache on the Celeron, compared to the 256K on the Coppermine. Instead of designing an entirely new core for the Celeron, Intel simply disabled 128K of the Coppermine's 256K L2 cache and then called it Celeron. Not only has the size of the cache changed, but the design has changed as well. Although both CPUs have a full 256-bit L2 bus, the Celeron only has a 4-way set associative cache, compared to 8-way for the Pentium III. The Celeron also runs on a slower 66 MHz FSB compared to the 100 MHz FSB of the Pentium III. All of these factors ensure that the Celeron will in no way be confused as competition for the higher priced Pentium III. Although it does not affect performance in any way, Intel has adjusted the core voltage to 1.5V for the FC-PGA Celeron, which is lower than the Pentium III's 1.60/1.65V default voltage.