– 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

This isn’t really a 5-year-old answer but there’s an equation that describes dynamic power consumption in CMOS devices, which is one of the more popular processes for fabricating CPUs.

P = C * V^2 * f

P is power, c is switching capacitance, V is voltage, and f is frequency.

If you want optimize power consumption, voltage matters a lot the operating frequency also matters. C naturally gets smaller with more advanced process nodes. Therefore, IPC or instructions per clock is quite important for efficiency.