Undervolting (AiGear) - how much power does it really save?

jeekub · Post by **jeekub** » Wed Jun 03, 2009 2:26 pm

I'm using ASUS M3N-Ht Dlx motherboard with AMD x2 4200+ (65W) The board features an utility (AiGear) to lower the voltage of the CPU.

The max attainable difference is 0,08 V - how much does it reduce power consumption? Is it worth using?

I have no idea about physics, so any help with explaining this would be much appreciated!

Esben · Post by **Esben** » Sat Jun 06, 2009 6:19 am

Lowering voltage is a great thing for reducing power consumption. But the amount of voltage reduction by AiGear is very small, so the resulting power consumption is not reduced much.

You can make a rough approximation of power consumption as:

P = C * MHz * V * V

So for your 0.08v reduction, from 1.35V which I believe is the default voltage of your CPU, reduces it to 1.27V.

Original power consumption:
P = C * 2300 * 1.35 * 1.35 ~ 4200 C

Undervolted power consumption:
P = C * 2300 * 1.27 * 1.27 ~ 3700 C

Thus your power consumption is reduced to (3700/4200) = 88 %

jeekub · Post by **jeekub** » Sat Jun 06, 2009 9:42 am

thanks!