What components add most to idle power draw and why?

norm

norm

norm

Soldato
Joined
21 Jan 2003
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If you take the below as an example.

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100w for a system idling is a significant amount of energy. Over the course of a day that's 2.4kWh.

Now I appreciate the hard disk motor is on all the time and using ~15w. And the PSU is adding to the load slightly because it's not 100% efficient.

But for the other components like CPU/motherboard/gfx, where is the power being used if the components are essentially idle?
 
Probably the gpu will be pulling a amount along with the motherboard and memory, but obviously these wont be as much.
 
V=IR and P=IV in simple terms, current flowing through electrical components will always use energy. There are tricks to reduce it and so on, but short of turning everything off you'll always have some power consumption.
 
Amd Fm2 has a really low power consumption in idle as all ivy bridge CPU
And about AMD GPU 7000 series will shut down under idle having 2W power consumption
A gold certified power supply has about 80% efficiency at 10-15% load
So you can go as low as 60W in idle with modern components
 
You can do much better than 60w....

I have a Celeron G530 in a mITX board with a gold 300W psu

Idles around 18W and primes around 41W.

While the Celeron brand may score mockery it's a 2.4Ghz dual core sandy brigde with inbuilt HD graphics more than enough for casual usage or as a media center.

Even an AMD X3 405E with an SSD and 3TB HDD will idle and under 40W from the wall socket.

In my experience the following impact most on power usage.

1) PSU typically 10-20% wasted energy can be much higher at low wattages especially for high capacity PSU. A 800W PSU may be only 60-70% efficient at 50W. Most people overestimate their PSU requirements so buy a unit that's less efficient at their actual consumption.

2) Fully featured motherboards with multiphase VRM's. The more phases in the VRM the less likely the motherboard is to be efficient unless it can shut down the phases in response to low power demands. Extra onboard features such as non native SATA, USB, Firewire, LAN , PCI-E lane multipliers etc all eat extra power. A simple cut down motherboard will use less power.

3) GPU's these often eat power as Aero fires up the 3D mode kicking in the faster clocks compared to 2D idle. Even a lowly 6450 takes around 10W at idle.

4) HDD's are less of an issue if they spin down, an SSD as the system drive uses little power so would allow the system to access without load. A multi platter high capacity HDD needs more power just to keep it spinning

5) Overclocking For stability it's common to disable power saving features and increase voltages = lots more power used.

6) Then you add in, TV card 10W, usb devices case fans

AD
 
I will have to disagree on the more phase regulators on the motherboard meaning higher power consumption
They work sharing the load, the number does not increase the power draw
A full ATX motherboard will have a higher power draw because of the extra features
If you wish for a low poser consumption PC get a:
http://www.overclockers.co.uk/showproduct.php?prodid=FS-000-IN&groupid=43&catid=2385&subcat=2253
http://www.overclockers.co.uk/showproduct.php?prodid=FS-004-SP&groupid=43&catid=2385&subcat=2253
The second has ram and hdd and wierless
 
I have a old P6T Deluxe V2 and i7 920 which I am using as a file server (bit OP lol) and I have tried everything to reduce the power usage i.e. right bios settings and removing anything not essential on the hardware side and it still takes about 102 watts at idle. Undervolting the cpu to 0.95 seemed to make the most difference as it dropped it from 160 watts.

Short of replacing the lot I am a bit out of ideas of how to reduce it further. I did wonder about replacing the cpu with a mobile version if that is possible although I am not sure if its just the mobo sucking up the juice.
 
a bit op..........:)
Give it to me i can make good use of that platform
But unfortunately there is nothing you can do to lower the power consumption any further
It might help to disable sound and other stuff on the motherboard that you do not use
 
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