To measure the power consumption of graphics cards, we use a simple measuring device produced by Conrad Elektronik (Energy Check 3000), which measures the power draw of the entire system, including motherboard, CPU, etc. The efficiency of the power supply we used during testing (Antec True Control 550W, 69% efficiency) is not factored into the results here. After all, you have to pay for the all of the electricity you use, regardless of whether it is lost to PSU inefficiency or actually used by the computer’s components.
For the sake of clarity, we would like to emphasize one thing again : The following numbers do not represent the power consumption of the graphics cards alone but that of the entire system, in this case obviously our review system. This measuring methodology, although simple, makes it very easy to get an idea of how power-hungry a graphics card is and compare its power consumption with that of their competitors.
To ensure that components such as optical drives and hard disks don’t factor into the final result due to activity, we measured the power consumption while going through the options of the BIOS. The new X800 cards require much less power than the Radeon 9800XT and are also less power-hungry than the GeForce 6800 Ultra.
The "2D Idle" measurement is taken after Windows XP has finished loading and started all its services (idle system). Both X800 cards prove to be very frugal and require less power than either the Radeon 9800XT or the GeForce 6800 Ultra.
These values represent the maximum power draw that we measured in the different Game Tests in 3DMark 2003 at different resolutions and quality settings (FSAA, anisotropic filtering). The X800 XT’s peak power consumption is slightly higher than that of the Radeon 9800XT. The X800 Pro, on the other hand, draws much less power. NVIDIA’s GeForce 6800 Ultra proves to be the most voracious.
ATi quotes the X800 XT’s power consumption in 3D games to be 67,48 Watts, while a Radeon 9800XT supposedly needs 67,54 Watts. This seems strange to us. In a later Email ATi started to talk about "average" power draw... A pretty useless information since the system power supply must be able to handle the peak power draw.
Using the 110-Watts of the GeForce 6800 Ultra as our point of reference, we had calculated a power draw of 91.5 Watts in our last article !
Since it is unlikely that NVIDIA would suggest a 480Watt power supply for the GeForce 6800 Ultra and equip the card with two power connectors if it weren’t really necessary, we can conclude that the quoted maximum power requirement of 110 Watts is correct. Factoring in the 69% efficiency of our power supply, the X800 XT required roughly 17 Watts less than the GF 6800 Ultra in our tests. That would put its power draw at about 93 Watts ! Of course, we should allow for a certain downward tolerance, as we can’t be sure that we actually achieved the 6800 Ultra’s "worst case" scenario in 3DMark 2003.