Four years is a long time. Just ask any college senior. Much can change in four years; in fact, the average college student changes their field of study as many as seven times in the course of their four year education.
Intel's Celeron processor was released back in 1998 - a short time ago compared to the lifespan of a Galapagos Tortoise, but a relative eternity in the processor industry. Like an evolving student, the Celeron has undergone its fair share of alterations, each one enhancing performance. Be it the 128KB of on-die cache or the addition of SSE, one aspect of the Celeron has remained constant; a 66MHz front side bus.
While a 66MHz bus worked wonderfully to segregate Intel's value and performance processors four years ago, it serves as a painfully obvious limitation on today's high-speed value parts. With a competing AMD Duron running a double-pumped 100MHz bus and a 133MHz memory bus, its no wonder comparably clocked Durons have torn the Celeron to shreds in terms of performance.
So you say Santa forgot to upgrade your dilapidated rig this Christmas? Maybe he knew something that you didn't. Our prayers have been answered at last, and after four years of Celeron processors running on a 66MHz bus, Intel is rolling out the Celeron 800 without a single architectural change. That does not worry us though, because this new Celeron is running on a 100MHz front side bus.
The Celeron is essentially a Pentium III Coppermine series CPU with 128KB of L2 cache, communicating with the chipset via a 100MHz FSB. They share the same SSE instruction extensions, architecture and technology. The Celeron and Pentium III are similar enough that they are even made from the same .18 micron die using aluminum interconnects. The Celeron comes packaged in the FC-PGA Socket 370 form factor and does not work with a Slot 1 motherboard without a socket adapter.