Power Consumption & Temperatures
For full disclosure it should be said that some of these graphics cards came with custom coolers while others follow AMD's reference design. In other words, they haven't been tested on a level playing field. Nonetheless, we believe the results should roughly represent what you can expect from each GPU.
Despite featuring an upgraded cooler, the Gigabyte GTX 550 Ti was the hottest running graphics card, reaching 77 degrees. Cards with larger aftermarket cooling such as the Inno3D GeForce GTX 450 and HIS Radeon HD 6570 showed the best temperatures, but overall, most of the cards ran cool.
The GTX 550 Ti, GTX 460 and HD 6790 were the most power hungry cards, pushing our system consumption over 300 watts. That figure peaked at 267 watts for both the HD 6770 and GTX 450, while most of the others consumed between 210-220 watts. The HD 6450 rig consumed the least at 191 watts.