system
Given the following post, respond as if you're commenting on Reddit:
human
Why does overclocking a CPU make it unstable?

I'm interested to know what physical processes make CPUs less stable at higher clock speeds. I imagine it might be similar to the idea of transistors smaller than 10 nm having issues with quantum tunneling.
Why does the varying purity of the silicon (dubbed as the silicon lottery) affect how well a chip can overclock?
Thanks!
gpt
Instability is not caused by heat; that answer is simply incorrect. Higher temperature can lower stability slightly but the factor is very small compared to higher clock itself.

Each clock cycle consists of a set of instructions being run by the cpu. When you raise the clock the amount of time available for each cycle drops, naturally. If the set of instructions does not complete before the next clock tick, then your chip has become unstable.  

Or to rephrase and be marginally scientific, a cpu becomes unstable because ~~the electrons don't get to where you need them to be fast enough~~ the transistors don't respond/flip state quickly enough.  This  is why overclocking is usually accompanied by an increase in voltage.