– Why does clock speed matter on a CPU, and why do some top-tier CPU’s have lower clock speeds than some from nearly 10 generations ago?

Question

I have a good understanding of what clock speed is, but why does it matter?

For the second question, I was wondering since for example, the new i9-14900K has a base clock speed of 3.2 GHz, whereas my previous desktop CPU, the i7-4790K, had a base clock speed of 4.0 GHz. Why hasn’t this number steadily gone up thought the years?

In: Technology

Answer 1

We are approaching physical limits to how much we can affect clock speed.

It can only operate at the speed of light. Just imagine you have a distance of 10 atoms to travel in a circuit.

This is unrealistically stupid small. Inconcievably tiny.

Now imagine you have a circuit that is 20 atoms to travel. This is still inconceivably small… but it would take *twice* as long still at the speed of light.

Now multiply this concept by *billions* of microscopic components all working together to get from input to output.

Ok with me so far? Now imagine you have those billion components in front of you (at a human scale like a giant warehouse). You have billions of wires with the components as well.

Your job is to interconnect all of these components (in order correctly configured) with the shortest possible distance between all of them.

We are at a point where the components can’t really physically get smaller. All that’s left is to arrange them in the most efficient configuration, such that an electronic signal travels a shorter path overall.

This is no easy task, and is why that clock speed number isn’t growing quickly.