texastailspin :
I am curious why CPU manufacturers are stuck at 3Ghz?
I understand we are utilizing multi core technology, increased the bus width and better use caching to give us the added horse power but that is only useful if your OS and Application can utilize it.
I will get this back on subject.
A single transistor can switch in the Terahertz range by itself and Intel has shown this off before (google it), however the copper wires and the distances between the transistors heavily limit us. We are hitting the limit of how fast electrons can flow through copper. Even though electrons can travel near the speed of light, as they pass through materials such as copper, they hit the nuclei of the copper atoms and bounce back and forth making the distance they actually travel forward somewhat slow. With all these collisions happening it creates heat due to the friction. Heat is a measure of how much an atom is vibrating back and forth. Because the copper atoms are vibrating so much it further increases the friction making even more heat while even more-so slowing down the electrons. This is why we try to keep our processors cool so we can overclock higher. With less collisions the electrons move onwards faster which can yield a higher clock speed. Also by making processors smaller it decreases the distance between the transistors which is 1 of the many reasons we are still slightly getting faster.
Processors will not get a significant clock speed increase until we use different materials. I personally think it would be great if we could build a transistor that could switch off of light. Then we should be able to hit terahert frequencies.
I am basing this off of what I know and it is kind of my theory, I did not research this so don't crucify me if I got something wrong.
Also I wanted to say I am amazed that some of you had to ask the op to rephrase and elaborate on the question. Really, is it that hard to understand? O ya, this is rhetorical, I don't actually care to read why.