At What Scale Does Quantum Mechanics Impact CPU Functionality?

[need_aca_help]

A few weeks ago I heard that Intel released 14nm CPU (Broadwell). After that I did some research and found out that by 2020s we humans will have 5nm CPUs and that will be the end of Moor's law according to Bob Colwell.

My question here is at what scale does the quantum mechanics kick in and classical computation can no longer be performed?

 

[UltrafastPED]

Quantum mechanics is already required to understand semiconductor devices ... like transistors.

Perhaps your question is "when will the limits of silicon technology be reached?"
http://www.intel.com/content/www/us/en/silicon-innovations/moores-law-technology.html

There are other technologies in the pipeline ... such as integration of graphene with silicon.