the r9 280 has 200w TDP, the gtx 960 has 120 and there are silent gaming versions. stop claiming false facts please.
having trouble with the math? no problem buddy, here ya go i even did it for you:
if 1 kwh is worth 0,25$ and you run your pc for 4 hours every day for gaming using 200w for gpu only
you will spend 20$ monthly on supplying your gpu with power.
if you had the 960 it would be 12 dollars a month for similar performance, saving you about 150$ in its lifespan compared to the r9 280.
so please finally buy one of the two and dont take kwa-e so serious, he even mistakes common sense for nvidea fanboyism.