Super_ :
Gam3r01 :
I wouldnt recommend it. As a single card is almost always better in terms of price/performance, scaling, and prower consumption. Not to mention the maxwell architecture is newer than the 290.
I could also do 3 r9 380s if those are maxwell.
Maxwell is Nvidia, 750, 750ti, 950, 960, 970, 980, 980 ti, and Titan X.