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The Power Saving Guide

Graphics Card

The following table lists the system power requirements when using several popular graphics cards. These results were obtained with a different motherboard than the one listed in our test setup, but the difference is clearly in the single-digit range and thus negligible. 2D reflects the power draw under Windows, while 3D represents the power requirements when running 3DMark06.

System Power Draw (W)2D3D
GeForce 8800 GTX SLI244.5435
GeForce 8800 GTX164258
GeForce 8800 GTS (640 MB) SLI222350
GeForce 8800 GTS (640 MB)136.5208
MSI GeForce 8800 GTS (320 MB) OC SLI219355
MSI GeForce 8800 GTS (320 MB) OC132204
GeForce 8800 GTS (320 MB) SLI219344
GeForce 8800 GTS (320 MB)130.5200
GeForce 8600 GTS (256 MB)96147
GeForce 7950 GX2 SLI190.5330
GeForce 7950 GX2125207
GeForce 7600 GT SLI122.5192
GeForce 7600 GT89131
GeForce 6800 GT SLI163265
GeForce 6800 GT108166
Radeon HD2900 XT CF215471
Radeon HD2900 XT142285
Radeon X1950 XTX CF134.5340
Radeon X1950 XTX103228
Radeon X1900 XT (256 MB) CF131328
Radeon X1900 XT (256 MB)103220
Radeon X1900 GT104.5198
Radeon X1300 XT CF112192
Radeon X1300 XT92.5152
Radeon X850 XT101.5189

Check list:

  • If you want to save energy, select a graphics card that offers both adequate performance and acceptable idle (2D) power requirements.
  • Do not use a discrete graphics cards in favor of a platform with integrated graphics if you want to minimize power requirements and heat dissipation.

Savings: The idle power requirements differ tremendously whether you run integrated graphics or a powerful discrete graphics card. Simple graphics cards consume as little as 25 W while high-end models require at least 40 W, whether they are active or not.

Display

When we talk about system power requirements of 60 to several hundred Watts, this number never includes the display! We already mentioned it: Turn everything off that you don't need. CRT monitors at 19" and up require at least 100 W; TFT displays start at 25 W and may go up all the way to 50 W, depending on the screen size. Power users tend to use two displays, while some people like our Webmasters even use three, which effectively can make your displays the real power eaters in the system. All displays are capable of going into a power saving mode, which reduces the power requirements to only a few Watts.

Check List:

  • Use power saving options to put displays in standby mode when they're not needed (especially if you have more than one display).
  • Switch off displays when you leave for the night.
  • Use smaller displays instead of multiple smaller displays.

Savings: This largely depends on the type of display. Since the display(s) typically are responsible for 20-30% of the system power draw, switching them off when they're not needed saves considerable energy.

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