7970 is a dual gpu video card, monster size, monster power, monster price but gets great performance.
Really it comes down to whats games you want to play the most, use that site I linked to compare cards for the games you want. Some games amd is better, some nvidia, some they are even, some were worse at the time the benchmark was done but are winning now with new drivers or game patches. lol. It's all very confusing.