Power Consumption of Contemporary Graphics Accelerators: Part1 -> ATI
 

Contemporary graphics cards surpass the older products across a number of parameters like speed, functionality, complexity and, alas, power consumption and heat generation. We would like to introduce to you a method of measuring power consumption – and heat dissipation, too – for modern graphics cards and will also share with you the results of the tests, for the card running at their nominal frequencies and after overclocking.


http://www.xbitlabs.com/articles/vid...powercons.html

Surprising factors on different rates of power consumption from the three voltage rails with different series of card.;)