Wow i am confused?
I am pretty much a noob with the technical aspects of GPU's and am getting ready to buy a evga gtx 780.
From reading this thread i better go with the gtx780 sc with 6g vram rather than get the 780 ftw 3g i originally had my eye on?
I game at 1920x1080p on a single monitor but i am starting to think that even 3g of Vram is not really enough for watch dogs and possibly other games to come at max texture settings?
As far as I'm aware, there are 4 games so far that run optimally with 3GB at full detail @1920x1080:
Rage
Wolfenstein: New Order
Watch Dogs
Rome II: Total War
Rage and Wolfenstein run on the same engine which uses Megatexture streaming which is unique to this engine. At the time Rage needed 3GB to run the highest resolution textures, but you couldn't configure it to do this inside the game.
Watchdogs is very much like GTA 4 in the way it is open world and needs to stream a lot of texture data to be playable with high resolution textures. At the time there was a lot of controversy with GTA 4 as it was the only game that needed this, but now with consoles having around 6GB (if you take the OS out of the equation) to pool between the CPU and Graphics, this could become a more commonplace technique.
I would say if you were planning on sticking with 1080p the 3GB should be enough. Generally developers will aim for the mainstream and with most AMD cards (and the higher end of Nvidia ) having 3GB, it wouldn't be in their interest to develop for the minority.
There are going to be occasional exceptions, like rage and GTA4, or possibly Skyrim modded to excess but generally 3GB will be enough for 1080p.
How overclockable is the 6GB version of the EVGA you are looking at? Generally I'd say the 6BG version would be aimed at the multiscreen market.