power concern with intel dg965wh MB

[ac71]

I have this computer with Intel DG965WH and E6300 running fine for a year or so. Recently I started playing with this kill-a-watt toy and noticed that in completely idle condition, it is consuming 90W. Not good, I realised that in idle condition, the cpu freq. is only varying from 1.86 to 1.6 ghz even though in vista power management it is told to go down as far as 50%. Latest bios didn't fix anything. Also, I don't see any setting in the bios to set acpi version (1 or 2 or 3 etc). Any clue ?

 

[akhilles]

No, I don't think kill-a-watt is wrong. The computer industry are exaggerating the power needs. Take my 4ghz o/c'ed pc for example. It uses less than 200 watts at idle. If you google around, you might find a short write-up on an 8800GTX PC using about 300-400w.

2nd, the cpu will throttle down at idle by default. Unless you disable C1E, EIST, thermal control in bios. Look at your manual in the bios section.

 

[ac71]

Thanks for reminding me about the biggest culprits when it comes to pc power consumption: the graphic card vendors! It is sad that they hardly provide any power saving mechanism in idle mode.

Anyway, my issue was cpu throttling, I have enabled EIST in BIOS and in vista power mgmt the cpu is allowed to go down upto 50% of its rated speed. But in reality it toggles between 1.86 and 1.6 ghz. I have searched the intel motherboard literature and found nothing else to be enabled. So, was wondering if anybody else had better luck on power management with this board (DG965WH) on vista.

 

[jaguarskx]

The efficiency of the power supply will determine how much power the overall system will consume. The higher the PSU's efficiency, the lower the overall power consumption.

Example: A typical PSU from a couple of years ago is about 65% - 70% efficient. Assuming at idle all components draws 75w of power. A PSU that is 70% efficient will waste 30% of electricity drawn of the AC outlet as heat. Therefore, a Kill-A-Watt will measure about 107w of power (75w / 70%). Thus, 32w is wasted as heat.

Currently a high quality PSU certified as "80Plus" will be at least 80% efficient at any given load. Some PSU can peak at 85% efficiency. Same situation above, a PC that consumes 75w of power will only waste 15% (under the best circumstances). That translates to 88w of power drawn for the AC outlet. That's 13w of power is wasted as heat.

 

[jaguarskx]

Power consumption of the video card while idling can be relatively low depending on the card.

Below is small example of mid to upper mid video card power consumption.

From:

Nvidia GeForce 9600 GT: Worthy Rival to ATI Radeon HD 3000 (page 7)


I use ATITool 0.27 to lower my X1900XT's core and memory frequencies (able to save profiles too). It also allows me to lower the voltage, it doesn't save voltage profiles. Therefore if I wanted to play a game I have to manually increase the various voltages before starting a game otherwise the PC will simply crash.

Not sure how much power I save but adjusting my X1900XT down from default to the following settings reduces the temperature by 6C when idling :

Core: 195.75MHz
Memory: 297MHz

Vcore: 1.2v
MVDDC: 1.785v (lowest setting) - memory
MVDDQ: 1.785v (lowest setting) - memory
VDDCI: 1.134v (lowest setting) - For the additional power connection