Looking to add more video horsepower, best way?

so I was looking to add some more umpf to the video card department buti have one question before I make a decision?

is there any thing I could get for ~$250 that would be more than 15-20% faster than a pair of 7870s?

the reason I ask is because if I cross fire a pair of 7870's I could get abit more video umpf for about $150.

but if I can get something that's going to have more gains than that for $250 I would do it. i'm just getting ready for things like GTA5 and watch dogs and up coming big games that aren't battlefield or call of doody.

you're forgetting about SLI scale-ability and the titles you're playing. two 7870's might not run 2x as fast.

i think this might help a little

http://www.videocardbenchmark.net/gpu.php?gpu=Radeon+HD+7870

spend 300 and get a gtx 770, sell the old 7870 to pay for the difference. :0