You should give your computer specs, what your running now. Monitor resolution.
Have you ever run a 2 -gpu setup ?
The fps or power in popular games will be much greater from 2 mid-high range cards (6850) vs one high end card (6970)
but there are trade-offs
I have :
CPU : AMD Phenom x2 955 3.2 ghz
MOTHERBOARD: msi 790FX-GD70(it supports cf)
GPU : ATI 4870 1 gb
MEMORY : 4 gb 1600
HDD : 750 gb
Monitor resolution : 1680x1050
Power Supply : Deluxe 600 W
OS : Windows 7 x64 Ultimate
I know that the fps will be better in popular games ,but I saw that the ram of the video cards dosent add up so in a game like GTA 4 will I be abel to play at full detail ?
Also is the 570 worth it ?
At that resolution and PSU, a single 6970 is going to be everything you need. You'll have great FPS in almost any current game without the headaches of crossfire. Your PSU is boarderline for crossfire anyways.
Well the 6850 is 1 gb ram (even in cf as ram is mirrored) while the 6950 and 6970 have 2 gb. From what I remember full details in GTA IV is video ram dependent so you might be better off with a 6950 or 6970 with more Vram if GTA IV is what you mainly want to play - will have more than enough power to max out the game.
Also have you considered getting 1 x 6950? - $70 cheaper (30-35%) and only 10% slower at tops so its a lot better deal. Then save the cash to get 2 x 6950 later as the scaling appears to be good
The prices over here are bigger , way bigger , the 6950 has the price of the 6970 . And I was giving and example about GTA 4 , I dont really like the game . What about Crysis 2 , I know it didn't come out yet but I wanna play it at full when it comes out . The games I play : Arma 2 , Americas Army , Red Orchestra , Crysis / Crysis Warhead , BF BC 2 . So whats better for this kind of games ?