Nvidia's GeForce GTX 960 graphics card reviewed
 

In virtually every case, you'll pay more for the Radeon than for the competing GeForce in other ways—whether it be on your electric bill, in terms of PSU requirements, or in the amount of heat and noise produced by your PC. The difference between the R9 285 and the GeForce GTX 960 on this front is pretty dramatic.

Another way to look at the plot above is in terms of progress. From the GTX 660 to the GTX 960, Nvidia improved performance substantially with only a tiny increase in measured power draw. From the GTX 770 to 970, we see a similar performance increase at almost identical power use. By contrast, from the R9 280X to the R9 285—that is, from Tahiti to Tonga—AMD saw a drop in power efficiency. Granted, the R9 285 probably isn't Tonga's final form, but the story still isn't a good one.

http://techreport.com/review/27702/n...-card-reviewed