Frequency

[StrangeQuark]

What is CPU frequency? I know that it is cycles per second (or billions of cycles per second now), but I want to know what it physically is. Is it the frequency of the current changes (impossible, if I'm right in thinking computers use DC), or what?

[zimv20]

i believe the strict definition is the rate at which the processor executes instructions. i don't know the physical process by which the crystal pulses those cycles.