> December 1998 $85 Celeron 300A handily beating June 97 $594 Pentium 233 MMX, not to mention overclocked one matching 1998 $621-824 Pentium 2s.
Ah, I remember the days of Intel's fabs doing “too good” a job and many more chips passing tests for faster use being produced than expected. To fulfil orders for the slower chips some of these better batches were marked down and sold as slower units, so if you were lucky you could really push the overclocking and get yourself a performance bargain. You also needed a good motherboard and quality RAM to pull it off reliably, of course.
Sillyrons is what we used to call the massively overclocked Celerons. At Uni a friend of mine made a good bit of pocket money from selling an optimisation service, for people who didn't feel confident playing with such settings themselves.
It wasn't just that. Mendocino wasn't a low bin, it was an entirely separate die from Pentium II. At the time, Pentium II used a 512kB off-die L2 cache, running at half cpu clock. To save on costs, Celeron 300A moved to a 128kB L2, which was integrated on the CPU die, and which ran at full cpu clock.
And it turns out that for a lot of software, a smaller but faster L2 was actually better than the bigger one. And because there were no fast products that used the Mendocino die, even the fastest of them were sold as Celerons. 300A was particularly nice because very nearly all of them could run at 450, and 100MHz FSB motherboards were widely available to pair with the fixed 4.5 multiplier of the CPU.