I was told that the CPU Clock is like a doorbell that informs the CPU about an upcoming program instruction. Each time an instruction is finished by the CPU, the clock can be “rang” again.
I understand that the CPU needs to take some steps to process an instruction. When all of these steps are completed, is this known as one “CPU cycle” and the amount of cycles per second is the clock rate measured in hertz? So would a clock rate of 3 GHz actually mean that the CPU can perform 3 billion instructions per second?
I find the CPU cycles and the clock rate a little difficult to understand. Because I’ve assumed that one cycle equals one processed instruction so 1Hz = 1 instruction but I’ve also read online that one instruction doesn’t always take one cycle.
So what exactly is one CPU cycle then and how does this correspond to the clock rate?
In: Technology
The clock ticks at a mostly constant rate, which may be infrequently switched to save power. A cycle is the interval between ticks. Every beat advances the work being done by the CPU by one unit. The processor may not fetch a new instruction with every tick if it is busy. A complex instruction is often broken down into several simpler operations, or the processor might wait x number of ticks for data to arrive from memory. If the program needs to wait, the processor still gets the clock ticks, but does one or more do-nothing instructions.
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