P3's went up to 1.4 GHz, as did their Celeron equivalent's. One of my lab machines is one of these 1.4 GHz Coppermines, and it is much faster than you would think.
These Coppermine core chips were much more efficient, cycle for cycle, than the P4's that replaced them. Their big liability was that they worked on a 100 or 133 MHz bus, whereas the later P4s were working at up to 800 MHz bus speeds. That meant that anything involving memory could be a lot faster on a later P4 than a P3, but in terms of raw CPU muscle-powered tasks, and for windows computing in general, in my lab, the P3 @1.4 runs about as fast as a P4@2.4 on a 400 MHz bus.
The Pentium M and Centrinos are evolved from the Coppermine core P3's, created by Intel's Israeli team as a wholy seperate branch from the P4. Basically think of them as P3's with SSE2 and more, and a higher memory bus speed.
The Core2 Duos are basically a pair of fast Pentium M cores slapped together with an even higher bus speed.
I'm greatly simplifying here, but the gist of things are that the NetBurst architechture of the P4 wound up be an evolutionary dead end, and the Coppermine P3 led directly down the Intel CPU branch we are enjoying today.
There's no doubt that the Core2 Duo's are really great. When my current rig, currently running the last, great overclockable and cool P4, the 3.0 GHz Northwood, is replaced, it's certainly going to be a Core2 Duo...
-Llama
