Why and How, are Computer speeds measured in Hertz?

[Newtons Apple]

Hey everyone. I'm beginning my exciting yet very nerve wracking road to a BS in computer science. I'm attending a university in NJ and hope to do well here. I love communications, networking, and all that jazz. Any who, one question has been bothering me. In my studying of computers, and how they work, I've run into one question that has been bothering me.

Why are computer speeds, (cpu, buses, and RAM) all measured in Hertz? To me Hertz describes something that's frequently 'waving' or counting. For example you can measure radio and gamma waves in hertz, because there's something moving in a frequent manner. But what's moving in a cpu that would allow it to be measured in hertz? When people refer to a CPU as having a 3.2 GHZ speed. It means that the processor is sending out info at 3 billion clock cycles.. But it just brings up the question, what is cycling? how long is a cycle measured?

The speed aspect of this is a bit confusing to me and I'd appreciate your discussion! I hope to hang out here on these forums, and gather as much information as possible, so excuse the elementary questions..

 

[rcgldr]

When people refer to a CPU as having a 3.2 GHZ speed, it means that the processor is sending out info at 3 billion clock cycles.

That 3.2 ghz speed is the clock input to the cpu (there could be a slower clock and clock multiplier in the cpu). The clock controls the timing of the gates inside the cpu, (the rate at which the gates can change states with some margin for transition and stabilizing time).

How the clock frequency is generated is through a very accurate clock generator, like a crystal, that then goes through a frequency multiplier that oscillates as some multiple of the clock generator input. The multiplier on it's own isn't that accurate, but is "tuned" at startup (or installation) to sync up with the slower but very accurate clock generator to end up with an accurate high frequency clock output.

 

[Newtons Apple]

hmm I think I get it... So the clock sets the tempo for all the chips on the board? Would that mean that the clock can beat at a faster speed than the CPU itself?

So the clock sends a unifying tempo to the entire mother board,telling everyone to beat at, let's say, 2.8 MHZ... then the CPU multiplies that so it can move a bit faster?

So each time the CPU and all the other chips send out and receive information, that counts as a cycle?

 

[DaveC426913]

Would that mean that the clock can beat at a faster speed than the CPU itself?

Indeed. Overclocking is the technique of speeding up the rate of the CPU.

Here's a primer: http://en.wikipedia.org/wiki/Overclocking

Chips can operate a lot faster than their rated clock speed, but start to get flaky. Manufacturers set the clock rate low enough to ensure no failures.

Your 3Ghz processor might be sped up to 4 or 5Ghz with no problem, but manus can't do this when they make them in bulk. Also, it will heat up a LOT more, and live a shorter life.

 

[LudusRex]

Computer speeds are measured in Hertz because it is a unit of measurement that represents the frequency of an oscillation or vibration. In the case of computers, it represents the frequency at which the electronic components, such as the CPU, are able to switch on and off. This switching is what allows the computer to perform calculations and process information. So essentially, the higher the Hertz, the faster the computer is able to switch and process information.

The reason for using Hertz as the unit of measurement is because it is a unit that can be easily understood and compared. Just like how we use miles per hour to measure the speed of a car, Hertz is used to measure the speed of a computer. It allows us to compare different computers and their processing speeds.

As for your question about what is cycling and how long a cycle is measured, it refers to the clock cycles of a computer. A clock cycle is the basic unit of time in a computer's central processing unit (CPU). It is measured in nanoseconds, which is a billionth of a second. So when a CPU has a 3.2 GHz speed, it means that it can perform 3.2 billion clock cycles per second.

I hope this explanation helps to clarify your confusion about computer speeds being measured in Hertz. As you continue your studies in computer science, you will learn more about the intricacies of how computers work and the various units of measurement used in the field. Best of luck on your academic journey!