Why dose the CPU Core Voltage float up and down a little at a steady state clock speed?

[ssote]

Why dose the CPU Core Voltage float up and down a little at a steady state clock speed, is it because of VRM spread spectrum or another Intel specification I don't know about?

[idata]

Hello:

Once again thank you very much to Ronin for all the information posted on this thread. To wingman99: We hope the information posted above was useful for you in addition to the previous comments submitted on this forum. Any questions, please let me know. Alberto

[ssote]

Ronin wrote:

Hi wingman99 ,

Your outlet voltage does not fluctuate in short time, but if you monitor for a day you will see that it fluctuates. Imagine that on CPU that day is a second ...

And yes PSU can compensate, but if you play a game, that uses intensively your video card, and measure the voltage you will see that the 12V will have a small variation.

On CPU when a transistor is turned on it adds a small impedance and that makes voltage drop and the voltage regulator rises the voltage back. There are also some small voltage stabilizers for each part of the CPU, inside of it, but they can't keep up perfectly with all those millions of very fast transistors turning on and off , that's why you see some voltage variations.

For the voltage to be perfectly stable it needs a voltage regulator with prediction, which needs to know exactly when each transistor is turned on or off to adjust the voltage. That you will never see

In conclusion that small voltage variation is normal and you don't have to worry about it.

Actually the reason why I made this post was to find out if it was the design of the Buck converter or VID operation that caused the fluctuation.

[CCris2]

That voltage is influenced also by power management of the CPU because even if CPU is on max multiplier, if a part of a CPU core is not doing anything the voltage of that part is lowered or maybe even turned off. So the voltage stabilization is very complex, with lots of factors that can influence it. The only way to make Voltage somehow stable is for the CPU not to have power management, and all parts of the CPU to be powered from a single rail, and that rail to have lots of amps, but then the CPU will get very hot and I don't think you want that

[idata]

Hello:

Once again thank you very much to Ronin for providing all the comments and examples on the previous posts. To wingman99: I hope the previous information clarify all your concerns about this subject. Any questions, please let me know. Alberto