Watts usage & algorithms

I would appreciate it very very much if someone could take the time to answer my question.

I'm trying to figure out an estimation of how much I'm paying per month on my computers watts usage. I am good with math but there are some things I'm not sure of

For ex. does the amount of watts used change depending on what I do on my computer? For example, would it be lower in idle and more while gaming.

Looked around and found these numbers:

On my ac adapter:

AC input - 100-240v 2A 50-60hz
DC output -19v 7.89A

On the cord (where u put it in the adapter), it says 7A 125v
On the back of the lappy (battery area), it says +19v -+ 19.5v 7.7A 150v (I'm assuming this is just for the battery)?

I mostly watch 1080p videos and my processor is never at 100%, maybe 60% or less.

I appreciate any useful info. Thanks in advance.

 

Hi Xellon!

The answer at that question is easy when it comes to estimation and gets difficult if you want to calculate the exact power consumption.​

Of course! In idle mode the power consumption is lower than the one when you are gaming or are running another application(s).​

This means that you can attach you power adapter to power grids at 115V (US) or 220V (EU) and the max power that your laptop can withdraw is 149.91W.​

It means that this cable is designed to transfer a current up to 7A at 125v. If your device requites higher current and you use this cable then the isolation will start melt and probably will cause fire.​

This info is about the unit’s max power consumption. It’s not related to the battery. ​

The process of watching video involves many things as storage, RAM, GPU, CPU, external peripherals. If you see in the task manager ~ 60% CPU load it means that CPU is consuming ~ 60% from its max power consumption. ​

The max power consumption of a unit can be calculated when you take into account any electronic component, attached devices and peripherals with their max power consumptions values. It’s not easy to put a laptop in a situation at max load because there are limits coded into the BIOS.

 

Awesome. Thanks for your reply.

+ rep

Also one more thing, If a computer does not have an ac adapter (my old desktop computer which just plugs straight into the outlet), does this mean it will always run at 115 watts (which is how much it consumes) constantly or does the above still apply?

 

It’s the same.

Let assume that your desktop computer has in e.g. 400W PSU. It doesn’t mean that your system consumes 400W constantly - depends from its current power mode, attached devices and load.

 

Use an outlet power meter.

 

All those numbers are ratings for the bits.

The cable can do 875W, the laptop can take 19-19.5V input from the AC, the adapter will take in at most 2A (which will actually be at the 100V rating).

These ratings will not give you your real usage (the voltages are constant but the current drawn will vary).

As said above a wall monitor will give you the best idea, if its idle for most of the time or doing 2d tasks its not going to cost much over a month.