7590 3gb at every time. Get it its a great card.
And for 1080p monitor will do very good. Will max every game u will throw at it http://www.tomshardware.com/reviews/radeon-hd-7950-review-benchmark,3207.html
And dont forget to choose the sapphire one
(thats the best card from 7950 )
Or asus if u want it to run cooler .