BeQuiet Dark Power 850

[artus]

will a BeQuiet Dark Power 850w be enough to crossfire 2 290's along with 4790 @ 4.4, 7 fans and 4 hard drives ?

 

[pastymuncher]

Just checked a load of reviews for power consumption figures and I have seen anything from 603-746w total system power consumption for a crossfire R9 290 setup. As you have 840w available on the 12v rail you have more than enough power to cover it.