The megahertz war is over
In the nineties Intel and AMD competed in the megahertz war to see who could overclock their chips to get the fastest headline grabbing chip frequencies.
The end result was that you couldn't get anywhere near the peak performance numbers and the thermal envelope went to the wrong side of 100W per chip.
When the single core chips were in danger of melting they jumped to multi-core.
We're now living with the fallout where the chip designers are retrofitting power saving features onto a power hungry design.
It's not their fault. The old mainframe technology was too expensive so people jumped away to cheap x86 hardware.
Now the pendulum is swinging the other way and lots of old technology (liquid cooling, thin clients (again), virtualization, etc) is being brushed off and given a new coat of paint.