– 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

Ok, virtually every other response in this thread is missing a big point. Unless you put the world’s worst cooler on an 14900K CPU it will literally never run at 3.2Ghz. Modern CPUs have what is called a boost clock, which, with proper cooling, is the speed that it will run at. The boost clock on a 14900k is either 5.9 or 6Ghz, I don’t recall offhand. In reality it can’t run it at that speed continuously, but it will run somewhere north of 5.5Ghz. They will automatically increase their clocks until they hit a temperature or power limit. AMD CPUs do something very similar, albeit at slightly lower clock speeds, 5.8-5.8Ghz and at much lower power draw.

On top of that the IPC, or the amount of work the CPU does each clock cycle is higher on modern CPUs.