A complete understanding if you ask me is one which requires no impenetrable "black-box abstractions" to be substituted in the abstraction hierarchy. In the case of a CPU, you would have to have a full gate level understanding of it and an understanding of how the gates operate.
To be honest, the "complete understanding" died way before the original post. It was the moment that they started building computers with integrated circuits inside them (before 1970) and complexity rocketed logarithmically. It died doubly so the moment that electrical engineering and the practical side of computer science diverged into "them" and "us".
If you want to use something which you understand, you will probably need to buy a crate of transistors, resistors and diodes and wirewrap yourself an entire computer from scratch PDP-7 style.
This fact is a warning: We really are building things with too deep abstraction hierarchies causing knowledge to be divided. One day we will never hope to comprehend anything in a lifetime.
To be honest, the "complete understanding" died way before the original post. It was the moment that they started building computers with integrated circuits inside them (before 1970) and complexity rocketed logarithmically. It died doubly so the moment that electrical engineering and the practical side of computer science diverged into "them" and "us".
If you want to use something which you understand, you will probably need to buy a crate of transistors, resistors and diodes and wirewrap yourself an entire computer from scratch PDP-7 style.
This fact is a warning: We really are building things with too deep abstraction hierarchies causing knowledge to be divided. One day we will never hope to comprehend anything in a lifetime.