Vcore oscillations

[gustavo]

When you take Vcore readings on your motherboards using any capable program, what kind of oscillationg around a central point you should expect (i.e. between 1.74 and 1.76 volts).

Should you expect a steady reading of 1.75 volts or any other number or is ok some oscillation ?

Apologize for bothering.
Gustavo.-

 

[Peter]

Those hardware monitor chip readings aren't too accurate - mainly because the reference voltage used also has its variations.

Processor manufacturers precisely specify by how much and for how long the Vcore may deviate from the regulation center point. AMD's Athlon XP datasheet and power supply design application note is excellent reading for those who want to learn more.

regards, Peter

 

[FenrisUlf]

Fluctuations can be caused by a weak power supply. When the CPU load and subsequently the power draw increases, a power supply that can't supply sufficient amperage will drop slightly in voltage. This is why overclockers always try to get good power supplies for those power hungry CPUs. I've seen 5v and 12v lines sag by as much as .2 to .5 volts when a large number of accessories (fans, CCD lights, etc.) are turned on. I wouldn't be worried by a .01 or .02 drop in Vcore, it could be resultant fluctuaion from the analog to digital conversion, but a .05 or more fluctuation, especially if it coincides with heavy CPU usage, is definitely cause for investing in a better power supply.

 

[Bozz]

That is the entire idea of a voltage regulator, to regulate the output voltage regardless of the input voltage so long as it is within specs.