system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why over the past 15 years, the typical CPU clock speed still remains around 2.8 to 3.2 GHz?

I know you can overclock the CPU to 5.0GHz, but I am not really talking about that.

Desktop CPU clock speed has increased from 1mhz to 2.8ghz over the past 40 years. But has remained at 2.8 to 3.2 average over the past 15 years...

Why not increase it along with other factors as well? What makes 3.0Ghz so perfect?

And if the clock speed is not the bottleneck, why do people that overclock the CPU see improvements in performance?
gpt
We're starting to run into some hard limitations of CPU manufacturing. The faster the clock speed, the more heat the chip will generate. If we push the clock speeds much higher than what they are today then people will need some exotic cooling solutions.

The normal way to increase clock speed without creating more heat is to make the wires thinner which lets the chips use less voltage. But, we're getting very close to fundamental limitations about how small the wires can be. They use to be able to pack twice as many transistors in the same space every 24 months or so. That pace has significantly slowed in recent years.

Finally, when you're talking about things happening in a billionth of a second, you start having problems keeping the entirety of the chip in sync. Electricity flows fast through the wires, but if we go much faster than the time it takes for the electrons to get from one side of the chip to the other will be slower than one clock cycle. This creates all sorts of new problems.