December 1998 $85 Celeron 300A handily beating June 97 $594 Pentium 233 MMX, not to mention overclocked one matching 1998 $621-824 Pentium 2s.
January 2002 $120 Duron 1300/Celeron 1300 beating 2000 $1000 Athlon 1000/Pentium 3 1000-1133
June 2007 $40 Celeron 420 overclockable out of the box from stock 1.6 to 3.2GHz beat best $1000 CPUs of year 2005 (FX-57, P4 EE).
Same goes for Graphic chips starting around 1998/9.
But the time since 2020 feels much faster again. It's scary! But it's exciting.
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.
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.
- AMD (K5/K6/K6-2/K6-III) - Intel (Pentium) - Centaur (IDT Winchip, later Via C3/C7/Nano) - Cyrix (6x86, 6x86MX) - Rise (mp6)